Final List of Nationally and Exceptionally Significant Features of the Federal Interstate Highway System

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Interstate Number	Resource Name	Property Type	Milepost [Range]	Year Construction Completed	Exclusion Criterion	Area(s) of Significance	National Register Criterion (A-D)	Date Listed on National Register OR Determined Eligible	Brief Statement of Significance
ALABAMA
I-65	Mobile Delta Crossing	Bridge	24.2 - 30.3	1980	2	Engineering			The Mobile Delta Crossing was designed by Howard Needles Tammen and Bergendoff and was constructed in 1980. The bridge crosses the Mobile-Tensaw Delta, which was recently named a National Natural Landmark by Congress. The Mobile Delta Crossing is 32,098 feet in length and covers slightly over 6 miles of bridge structure. The main span is a distinctive tied-arch bridge made of weathering steel that spans 800 feet. One of the few tied-arch bridges in the U.S., this type was chosen for the Mobile Delta Crossing for its ability to span a great distance and for the design's cost effectiveness.
ALASKA
Alaska Hwy (A-2)	Robertson River Bridge	Bridge	1353	1944	4	Military History, Engineering	A, C		The Robertson River Bridge is associated with the construction of the Alaska Highway from 1942-1944 by the U.S. Army during World War II. The Alaska Highway was built as a land transport route in the event that the Japanese seized shipping lines in the Pacific and to connect and supply a chain of strategic military airfields in all weather conditions. This bridge is one of three truss bridges in the U.S. portion of the Alaska Highway that retain integrity from the World War II period of significance.
Alaska Hwy (A-2)	Johnson River Bridge	Bridge	1380.5	1944	4	Military History, Engineering	A, C		The Johnson River Bridge is associated with the construction of the Alaska Highway from 1942-1944 by the U.S. Army during World War II. The Alaska Highway was built as a land transport route in the event that the Japanese seized shipping lines in the Pacific and to connect and supply a chain of strategic military airfields in all weather conditions. This bridge is one of three truss bridges in the U.S. portion of the Alaska Highway that retain integrity from the World War II period of significance.
Alaska Hwy (A-2)	Black Veterans Memorial Bridge	Bridge	1399	1944	4	Military History, Engineering	A, C		The Big Gerstle River Bridge was re-named as the Black Veterans Memorial Bridge in 1993 by a bill sponsored by Rep. Bettye Davis of Anchorage. Naming of the bridge, built in 1944, recognizes and commemorates the black soldiers of the U.S. Army Corps of Engineers for their contribution in constructing the Alcan Highway, now known as the Alaska Highway, from 1942-1944 during World War II. The Alaska Highway was built as a land transport route in the event that the Japanese seized shipping lines in the Pacific and to connect and supply a chain of strategic military airfields in all weather conditions. This bridge is one of three truss bridges in the U.S. portion of the Alaska Highway that retain integrity from the World War II period of significance.
ARIZONA
I-10	Deck Park Tunnel	Tunnel	144.5 - 145.5	1990	2	Engineering, Social history			This section was the last piece of I-10 to be finished, making the I-10 a continuous transcontinental route. The Papago Freeway was built partly as a depressed freeway. It is covered by 19 side-by-side bridges that form the foundation for a 12-hectare urban park. A graceful arched bridge maintains traffic on the historic alignment of Central Avenue and allows pedestrians to cross the freeway. The Margaret T. Hance Park was built on the deck to establish a connection between the neighborhoods bisected by the freeway.
I-15	Virgin River Gorge	Highway Segment	13 - 22	1973	2	Engineering, Environmental movement			I-15 through the Virgin River Gorge is a scenic wonder through a 500 million-year-old gorge. Construction of I-15, which opened in 1973, included re-channeling the Virgin River 12 times. “Somehow,” Arizona Highways magazine said in 1988, construction of I-15 “enhanced rather than distracted from nature’s handiwork.”
ARKANSAS
I-55	Memphis and Arkansas Bridge	Bridge	Connects West Memphis, AR with Memphis, TN	1950	3	Engineering	C	Listed 2/16/2001	The Memphis and Arkansas Bridge was listed in the National Register on 2/16/01 for its engineering significance. Completed in 1950, it is the only bridge spanning the Mississippi River that was designed exclusively for vehicular traffic. It is a continuous Warren truss, through truss, with verticals. The bridge is a total length of 5,222 feet and was designed by the firm of Modjeski and Masters.
I-40	Hernando DeSoto Bridge	Bridge	Connects West Memphis, AR with Memphis, TN	1973	2	Engineering			Designed by Hazelet and Erdal and the Tennessee State Highway Department, the Hernando DeSoto Bridge crosses the Mississippi River and contains two 900-foot tied steel arch spans and five continuous steel box girder spans. The approaches and connecting ramps to the west consist of continuous, composite pre-stressed concrete I-beams and steel-plate girders. It was named for Hernando DeSoto, European discoverer of the Mississippi River in 1541, but is sometimes called the "M" Bridge, because the bridge features a distinctive "M" shape which was outlined with lights in 1986. Contractors for the bridge included Bethlehem Steel Corporation for the superstructure and Massman Construction Company and Al Johnson Construction Company for the substructure. Sitting on the edge of the New Madrid Seismic zone, the second highest earthquake risk zone in the U.S., the bridge has recently gone through a seismic retrofit costing roughly $170 million.
CALIFORNIA
I-80	San Francisco - Oakland Bay Bridge	Bridge	SF 4.8 - 8.9 ALA 0.0 - 1.2	1936	1, 3	Architecture, Engineering	C	Listed 8/13/2001	In 1929, President Herbert Hoover, a Californian and engineer, and California Governor C.C. Young created a commission that concluded the economic need and construction feasibility of the San Francisco - Oakland Bay Bridge despite the obstacles presented by earthquake faults and lack of a solid anchorage on the muddy bottom. Hoover personally expedited War and Navy Department approvals and federal financial support. Contracts for the first construction were awarded in April 1933, and the San Francisco - Oakland Bay Bridge was opened to vehicular traffic on November 12, 1936. Loans for the total cost of $77.6 million were paid off by tolls within 20 years. "Upon its completion, the Bay Bridge was recognized as the greatest bridge in the world for its length, cost, weight, depth, amount of steel and concrete used, number of piers, and versatility of engineering." (http://www.lib.berkeley.edu/news_events/exhibits/bridge/sfobay.html).
I-80	Truckee River Canyon	Highway Segment	NEV 0 - 10	1964	2	Engineering			This stretch of I-80 over Donner Summit, through the Truckee River Canyon, was considered a major engineering triumph for the time. The American Society of Civil Engineers named it one of the two best engineering feats of 1964 (the other was NASA's Cape Kennedy).
I-105	Glenn Anderson (Century) Freeway	Highway Segment	LAN 5 - 18	1993	2	Engineering			The I-105 Glenn Anderson Freeway/Transitway (formerly the Century Freeway) was one of the last of the urban interstates to be built. It has been called Los Angeles County's "first high-tech roadway" because it features the latest in highway technology, including sensors buried in the pavement and links to computers that allow technicians to monitor traffic flow. Meters help regulate traffic on ramps connecting I-105 to four freeways. There are closed-circuit television cameras to alert officials to accidents or other incidents. Green Line light rail trains operate in the median. In addition, after being added to the Interstate Highway System in 1968, this freeway is associated with one of the earliest Environmental/Civil Rights lawsuits in California. The 1972 class action suit and community concerns about the route, which cut through predominantly African American neighborhoods and would displace hundreds of residents, halted construction. The freeway finally opened to traffic in 1993.
I-5	Chicano Park	Park	SD 14 - 14.1	1970	2	Social history			Adjacent to the I-5 right-of-way is a section of Chicano Park, established in 1970 by Chicano activists. Construction of I-5 in 1963 bisected the Barrio Logan neighborhood. Construction of the San Diego-Coronado Bay Bridge in 1969 further disconnected the community and resulted in the displacement of many residents. The bridge's on-ramps and support pylons were decorated with many politically-themed murals created by local activist-artists. FHWA determined the park to be eligible for the National Register by a consensus determination with the California SHPO for its association with an important historical event, the Chicano civil rights movement, as well as its contribution to the arts.
I-8	Pine Valley Creek Bridge	Bridge	SD 41.7	1974	2	Engineering			The Pine Valley Creek Bridge was the first concrete bridge in the U.S. built by the segmental cantilever method. The bridge superstructure was cantilevered out from the piers, segment by segment, until the two cantilevered sections met at mid-span. This was done as an alternative to building a ground-supported formwork for pouring the concrete, as is typical of smaller bridges, because the superstructure of the Pine Valley Creek Bridge is more than 300 feet above the ground at its midpoint. The bridge has a center span of 450 feet, probably the longest box-girder span in the country at the time of its completion, according to the Engineering News Record, July 1, 1971.
I-5	Pit River Bridge	Bridge	SHA 28.1	1941	4	Engineering	C	Eligible 2000	The Pit River Bridge was a major engineering feat because of its height, and it is a very large steel truss. It rests on piers that are hundreds of feet tall, but underwater.
COLORADO
I-70	Glenwood Canyon	Highway Segment	118.5 - 130.3	1993	2	Engineering, Social history			Environmental concerns halted construction of I-70 through the 2,000-foot-deep Glenwood Canyon in the late 1960s. The innovative design by Joseph Passonneau and Edgardo Contin met the challenge of complying with the AASHTO design standards while protecting the natural beauty of the canyon. The profile of the roadway was reduced by stepping westbound lanes above eastbound lanes, cantilevering roadbeds to reduce visibility of retaining walls, utilizing slender camouflaged columns and piers for the bridges and viaducts, and replanting construction scars with native shrubs and trees.
I-70	Eisenhower-Johnson Memorial Tunnels	Tunnel	213.7	1973 (WB bore); 1979 (EB bore)	2	Engineering	A, C	Eligible 2006	The Eisenhower-Johnson Memorial Tunnel (EJMT) was, for its time, a groundbreaking feat of engineering planning and design. The construction of I-70 and the EJMT through the Rocky Mountains was a major accomplishment toward the completion of the Interstate Highway System. It was the nation's most expensive highway project up to that point and remains the world's longest (at 1.7 miles) and highest (over 11,000 feet) underground thoroughfare. The EJMT stands as one of the great engineering achievements of 20th century highway design.
I-70	Vail Pass	Highway Segment	180 - 195.2	1978	2	Engineering, Environmental design parameters			Construction of Vail Pass set a new standard for environmental sensitivity and mitigation (an early representation of context sensitive solutions). The project was one of the first Colorado highway undertakings to purposefully sculpt cut and fill slopes to fit the unique setting and was landscaped primarily with native flora. It also was the first Colorado project to use precast and cast-in-place segmental bridges, some of the earliest such features in the country.
I-70	Genesee Park Interchange	Bridge	253.5	1970	2	Engineering, Context Sensitive Solutions	C	Eligible 1988	The single-span Genesee Park bridge was the first continuous steel box girder bridge built in Colorado. The structure design eliminated a center pier in order to allow westbound travelers an unobstructed, picturesque view of the Rocky Mountains as they approach the interchange at the top of a hill.
I-25	Arkansas River Bridge	Bridge	97.6	1958	2	Engineering	A, C	Eligible 10/1/2001	The Arkansas River Bridge is technologically significant as a long-span example of a steel plate girder structure and represents one of the most important river crossings on I-25. It is distinguished by its cantilevered construction, relatively long spans, and excellent state of preservation.
I-25	Speer Blvd. Underpasses	Bridge	211.5	1952	4	Engineering	A, C	Eligible 10/1/2001	The I-25 corridor through central Denver ("Valley Highway") played an important part in the post-World War II development of the city. The original overpasses and underpasses along the Valley Highway, of which the Speer Blvd. Underpasses are an example, played an integral role in the highway's function. They marked the first concerted use in Colorado of concrete rigid frame bridges, a technologically important structural configuration developed principally for urban streets.
I-25	23rd Avenue Underpass	Bridge	211.2	1952	4	Engineering	A, C	Eligible 10/1/2001	The I-25 corridor through central Denver ("Valley Highway") played an important part in the post-World War II development of the city. The original overpasses and underpasses along the Valley Highway, of which the 23rd Avenue Underpass is an example, played an integral role in the highway's function. They marked the first concerted use in Colorado of concrete rigid frame bridges, a technologically important structural configuration developed principally for urban streets. The 23rd Avenue Underpass retains good physical integrity and embodies this structural type.
CONNECTICUT
I-84	Morgan G. Bulkeley Bridge	Bridge	62.6 - 62.8	1908	1	Engineering	A, C	Listed 12/10/1993	The Morgan G. Bulkeley Bridge is a nine-span stone arch bridge measuring 1,192 feet in length. It carries what is now I-84 over the Connecticut River between the cities of Hartford and East Hartford, Connecticut. The bridge was designed by the team of Edwin D. Graves, chief engineer, and Edmund M. Wheelwright, architect. An unnamed engineer on the project speculated in 1926 that this bridge would probably be the last monumental stone bridge that would ever be built. This speculation proved to be true.
DELAWARE
I-295	Delaware Memorial Bridge	Bridge	Connects New Castle, DE, with Pennsville, NJ	1951, 1968	1	Transportation, Engineering, Social history			The Delaware Memorial Bridge over the Delaware River links Delaware and New Jersey via twin suspension spans between New Castle, Delaware, and Pennsville, New Jersey. The world's longest twin suspension bridge, it serves as a major link in the transportation system for the Eastern U.S. The bridge's first span (opened in 1951) carries drivers into New Jersey, and the second (opened in 1968) carries drivers into Delaware. Both spans are 3,650 feet long and look identical, though there are slight differences between them. The bridge is dedicated as a memorial to the military personnel who gave their lives in World War II, Korean War, Vietnam War, and Operation Desert Storm. An annual memorial ceremony is held on Veterans Day at the Bridge War Memorial, which overlooks the Twin Span. The Delaware Memorial Bridge is a self-supporting toll bridge operated by the Delaware River and Bay Authority, a bi-state agency.
FLORIDA
I-275	Bob Graham/ Sunshine Skyway Bridge	Bridge	0.0 - 4.1	1987	2	Engineering			This four-lane pre-stressed concrete cable-stayed bridge was constructed between 1982 and 1987 to replace the previous Sunshine Skyway bridge, which was destroyed when a freighter collided into it in 1980. The new bridge, designed by Figg & Muller Engineering, was awarded the Presidential Design Award from the National Endowment for the Arts in 1988. It is one of the first cable-stayed bridges with the cables attached at the center of the roadway instead of at the outer edges. There are 21 steel cables carrying the weight of the structure. The longest span is 1,200 feet. Large concrete bumpers, called dolphins, are located around the piers to protect them from future freighter impacts. This bridge connects southern Pinellas County with Manatee County. The elegant engineering design of this bridge provides it "exceptional importance". It is included in both Historic Highway Bridges of Florida books as a significant, modern example of bridge engineering.
I-75	Alligator Alley	Highway Segment	19.6 - 49.3	1989	2	Engineering, Transportation, Social history			The I-75 corridor from the tollbooth outside of Naples to the tollbooth west of Andytown was built as the premier environmentally sensitive facility of its time. It included design features that provided for the flow of water through the Everglades and the movement of wildlife across the corridor while providing the motoring public access from the east to the west coast of Florida.
I-75	I-75 Snake Wall	Overlook, Animal Barrier	8.6	1998	2	Conservation, Architecture			The I-75 Snake Wall sits along the edge of the southbound rest stop of I-75 at the north edge of Paynes Prairie, one of Central Florida's most important and sensitive ecosystems. The FDOT designed the wall to provide access to the Paynes Prairie Overlook and to serve as a barrier between rest stop visitors and the animals inhabiting Paynes Prairie, especially the snakes. It is shaped like a serpent with its forked tongue extended. The tongue is a functional part of the barrier. It runs from the head of the Snake Wall toward the roadway to help keep the reptiles away from the interstate roadway as well as the rest area. As a result, the I-75 Snake Wall is a unique piece of functional art and a successful effort at combining ecosystem and roadway management.
I-95	Myrtle Avenue Overpass	Bridge	3.2	1957	2	Engineering	C		The Myrtle Avenue Overpass carries I-95 over Myrtle Avenue and a railroad line in downtown Jacksonville. The main, steel arch span of the overpass is 386 feet long. There are 16 steel girder approach spans that bring the total length to over 1,400 feet in length. This bridge represents Florida's only steel arch, the state's only through arch carrying interstate traffic, and the only arch design serving as a grade separation. It was identified in an update to Florida's historic highway bridge inventory, and, as a result, the FDOT and the Florida SHPO concurred that this bridge represents a significant historic resource for the state.
GEORGIA
No recommended elements
HAWAII
H-3	Trans-Koolau Route	Highway Segment	4.2 - 7.9	1997	2	Engineering, Social history, Environmental movement			First planned in 1966, construction of this segment of H-3 was delayed for 30 years because of environmental concerns related to the Endangered Species Act and the National Historic Preservation Act. Among the most innovative engineering elements are the North Halawa Valley Viaduct, Windward Viaduct, and the Harano Tunnel. The North Halawa Valley Viaduct is an approximately 1.2-mile segmental cast-in-place post-tensioned concrete box-girder bridge, which was built by the cantilever construction method. Instrumentation has been included in order to monitor the creep and shrinkage strains in the structure. The Windward Viaduct is 80 to 130 feet above the Haiku Valley and is just over 1 mile in length. Self-launching trusses delivered the pre-cast concrete segments over completed spans for placement in balanced cantilever alignment, eliminating the need for crane access to the valley floor. The Harano Tunnel was constructed through a variety of volcanic geological conditions for nearly 1 mile. H-3 won the 1998 Outstanding Civil Engineering Achievement award from the American Society of Civil Engineers.
IDAHO
No recommended elements
ILLINOIS
I-74	Iowa-Illinois Memorial Bridge	Bridge	Connects Bettendorf, IA with Moline, IL	1936	4	Engineering, Architecture	A, C	Eligible 8/31/94; 10/16/2002 (two nomination forms)	The Iowa-Illinois Memorial Bridge over the Mississippi River was previously determined eligible as an individual structure for the National Register as part of a statewide study of DOT bridges in Iowa. The bridge was found to be eligible under Criterion A "as the largest, most important federal works project in Iowa" and under Criterion C because "it possesses a high degree of technological" importance. The bridge also is significant as a rare bridge type, as the work of an important engineer (Ralph Modjeski), and as one of the "Great River" bridges built over a major river. Additional historical significance is derived from the fact that it was a Depression-era PWA project.
INDIANA
No recommended elements
IOWA
I-74	Iowa-Illinois Memorial Bridge (see entry under Illinois)
KANSAS
No recommended elements
KENTUCKY
I-64	Cochran Hill Tunnel	Tunnel	9	1974	2	Engineering, Transportation			The Cochran Hill Tunnel, on the east and west sides of I-64, is of exceptional significance to the development of environmentally sensitive design in the area of transportation engineering. These underground tunnels were constructed in 1974 to preserve the National Register site directly above the highway. The site is Cherokee Park, a verdant landscape designed by Frederick Law Olmsted, which is part of the larger Olmstead Park system in Louisville. Kentucky Highway engineers and Vollmer Associates, Inc., in consultation with the general public, developed these environmentally sensitive tunnels to avoid destroying the important Olmstead landscape. These unique, groundbreaking tunnels were the first attempts to ameliorate the effects of highway construction on a Kentucky roadway.
I-64	I-64 Eastbound Rest Area	Rest Area	100	1960s	2	Architecture, Transportation			The best of three remaining 1960s modernist rest areas in Kentucky, the I-64 Eastbound Rest Area is significant in the area of architecture and transportation. This structure possesses exceptional significance and integrity and is one of the last representatives of modern style rest areas in Kentucky. In a design that recalls the architecture of the National Park Service's Mission 66 comfort stations and visitor centers, this rest area employs modern materials and design. I-64 Eastbound Rest Area is a one-story circular building, covered by a radial folded plate roof that creates a deep overhang for a walkway. The primary cladding materials are spandrel panels and textured pre-cast concrete walls. Transom windows and single light plate glass windows provide natural light on the interior. A mosaic wall mural located on the interior illustrates a map of Kentucky highlighting tourist destinations and principal cities in the state.
I-24	Whitehaven (Anderson-Smith House)	House, Rest Area, & Welcome Center	7	c. 1850	3	Social history	C	Listed 1984	The Anderson-Smith House is significant architecturally as a mid-nineteenth century house remodeled in the Colonial Revival period. In 1983, the mansion was restored and incorporated into the I-24 system as a rest area and welcome center. According to the nomination, it is the only historic house restored as a rest area on the Interstate Highway System by the early 1980s.
LOUISIANA
I-310	Hale Boggs Memorial Bridge	Bridge	6 - 7	1983	2	Engineering			The Luling-Destrehan Bridge, also known as the Hale Boggs Memorial Bridge, carries I-310 over the Mississippi River, west of New Orleans. Built in 1983 at a cost of $185 million, it is the first major steel cable-stayed bridge built in the U.S. Its total length is 2,744 feet, with a main span length of 1,235 feet. The American Society of Civil Engineers named the Hale Boggs Bridge as the Outstanding Civil Engineering Achievement for 1984.
I-10	Calcasieu River Bridge	Bridge	28	1952	4	Transportation	A	Eligible 2006	The Calcasieu River Bridge was constructed as a high rise to allow vehicular traffic to cross the Calcasieu River without being stopped by marine traffic. Before completion of this bridge, vehicular traffic was stopped at least 435 times per month for the Willow Drive Bridge to open and allow marine traffic to travel on the Calcasieu River. Riverine traffic was increasing due to the growing petrochemical industry and vehicular traffic was increasing due to the growing motor freight industry and the popularity of cars. This bridge became part of the Interstate Highway System when I-10 was constructed.
MAINE
No recommended elements
MARYLAND
I-68	Sideling Hill	Roadway, visitor's center, pedestrian bridge and walkway	74.5-73.5	1991	2	Engineering, Geology, Social history			Construction of the highway segment of I-68 in western Maryland that includes the crossing of Sideling Hill required the removal of 3.44 million cubic meters of sedimentary rock, revealing 350 million years of geological history. Elements include an exhibition and tourist center with geological displays and a pedestrian bridge and walkway for close inspection of the mountain cut and geologic layers. The pedestrian bridge is a voided slab with a "Leaping Stag" substructure covered in concrete. According to the Maryland Geological Survey, at Sideling Hill "almost 810 feet of strata in a tightly folded syncline are exposed in this road cut."
I-95	Fort McHenry Tunnel	Tunnel	4.8 - 6.1	1985	2	Engineering			The Fort McHenry Tunnel was the final link of I-95 and is the longest and widest vehicular tunnel ever built using the immersed tube method. It also is the first tunnel in the world to have sections with both horizontal and vertical curvature. Construction was accomplished by prefabricating the tunnel sections, floating them into Baltimore Harbor, and sinking them into place. It received the 1986 Outstanding Civil Engineering Achievement award from the American Society of Civil Engineers.
I-895	Baltimore Harbor Tunnel	Tunnel	2.4 - 3.8	1957	2	Engineering, Transportation			The Baltimore Harbor Tunnel is a component of the 17-mile long Harbor Tunnel Thruway and is part of a system of approach roads and ramps connecting the major north-to-south highways of the region in which it is located. Completion of this transportation project in November 1957 was an important step in the elimination of natural barriers to commerce and transportation in a major urban area. The Thruway was the first freeway for northeast corridor traffic through the Baltimore area and a major step in elimination of the so-called "Baltimore Bottleneck," which had increasingly become a major transportation problem since the 1940s. This was the longest twin tube trench type tunnel in the world when completed. Its construction was heralded as a major engineering feat of interest to engineers across the country. Prefabricated tunnel sections were sunk in an open trench dredged from the Baltimore Harbor bottom and then joined underwater. Excavation of the trench began in 1955, and the tunnel opened to traffic on November 29, 1957.
MASSACHUSETTS
I-93	Zakim Bridge	Bridge	18.6	2003	2	Engineering, Transportation			The Leonard P. Zakim - Bunker Hill Bridge, crown jewel of Boston's Central Artery/Tunnel Project (the Big Dig), is the widest cable-stayed bridge in the world. Developed by HNTB Corporation and Figg Bridge Engineers from the original design idea of Christian Menn, the bridge carries I-93 over the Charles River and serves as the northern gateway into Boston. It is the first asymmetrical cable-stayed bridge in North America, the first to use an ungrouted cable stay system, the first to combine a steel main span with concrete back spans, and the first to use a composite concrete tower with a high-performance steel inner core, among other innovations. The bridge's exceptional engineering qualities contributed to its selection by the American Society of Civil Engineers as the Outstanding Civil Engineering Achievement of 2004, and its dramatic visual character has already made the bridge a new symbol of Boston's civic pride.
I-95	Whittier Bridge	Bridge	86.2	1954	4	Engineering, Transportation	A, C		The Whittier Bridge is a double-barreled 3-span continuous steel "swinging" through/deck truss structure originally built to carry a relocated section of US-1 over the Merrimack River between Amesbury and Newburyport in Massachusetts. The central span is arched, and the highway deck is suspended from the lower chords by steel cables. The relocation of US-1 was intended to take the heavy through traffic formerly carried by US-1 over an aging drawbridge in downtown Newburyport. The present, high-level fixed bridge and its relocated approach highways were later taken into the Interstate Highway System as part of I-95.
I-95	Central Avenue Bridge	Bridge	36.1	1953	4	Community planning, Engineering, Transportation	A, C		The double-barreled Central Avenue Bridge originally was built to carry Boston's Southern Circumferential Highway (ST 128) over a local street in Needham, Massachusetts. It is one of the best-preserved surviving bridges dating from the 1940s/50s reconstruction of this, the first limited-access circumferential highway in the U.S. The Central Avenue Bridge's concrete rigid frame structural type is uncommon in Massachusetts; its stone-faced abutments and median wall, and its modestly ornamented steel railings, are typical of the "Fifties Modern" aesthetic of its time.
MICHIGAN
I-94	Blue Water Bridge	Bridge	Connects Port Huron, MI with Sarnia, ON	1938	1	Engineering			The Blue Water Bridge is a major international crossing over the St. Clair River that opened in 1938, linking Port Huron, Michigan and Sarnia in Ontario, Canada. This steel cantilever through truss bridge has a main span of 871 feet, anchor arms 326 feet long, and approaches consisting of deck girder spans and two deck truss spans adjoining the anchor arms on both the U.S. and Canadian sides. The bridge was designed by the well-known Pennsylvania firm of Modjeski and Masters.
I-94 I-69	Blue Water Bridge (2nd Span)	Bridge	Connects Port Huron, MI with Sarnia, ON	1997	2	Engineering			Jointly owned and maintained by the U.S. and Canada, this second span for the Blue Water Bridge was constructed to alleviate congestion at the nation's second busiest border crossing. The bridge is 6,109 feet long and is a continuous tied arch bridge over the St. Clair River. This construction design was chosen because it blends in with the original span, yet stands out on its own.
I-75	Landscaped Median	Median	292 - 295	1962	2	Landscape Architecture			A three-mile corridor located between Gaylord and Indian River is significant for the extraordinarily wide median designed to maximize scenic vistas. This stretch of interstate won an award for most beautiful highway from Parade Magazine.
I-75	Rouge River Bridge	Bridge	43	1967	2	Engineering			The Rouge River Bridge is significant for its vertical clearance of 101.7 feet. In this location, a drawbridge would cause unacceptable delays and safety conflicts for both motorists and water traffic. As a result, a new solution had to be created to allow both vehicular and water traffic to pass in this area. The height of the Rouge River Bridge provides unimpeded clearance for ships underneath and a roadway for vehicular traffic to cross the river.
I-75	Zilwaukee Bridge over the Saginaw River	Bridge	153 - 154	1988	2	Engineering			The Zilwaukee Bridge was a massive and controversial project that included a major construction accident. The 26-span bridge runs 8,085 feet with a vertical clearance of 119.8 feet, replacing a ca. 1960 bascule bridge. The Zilwaukee Bridge was designed to relieve traffic congestion along the freeway crossing that resulted from repeated openings of the original drawbridge for lake freighter traffic serving industrial sites along the river. It also is a substantial example of cutting-edge technology, as it used a balanced cantilevered construction method and interior cables to support the structure. In addition, because of the size of the bridge, portions were fabricated on site in a specially built facility.
I-696	Oak Park Pedestrian Plazas	Pedestrian Bridge	12, 13	1987	2	Social history			Wide landscaped plazas across this more recent expressway provide a safe and relatively secluded crossing for pedestrians. The plaza crossing is particularly important for members of Oak Park's Orthodox Jewish community, which rely on them for their walk to and from Temple on the Sabbath and High Holy Days.
I-496	Snow Road Bridge	Bridge	2	1969	2	Engineering			The Snow Road Bridge has a unique "V" center pier, one of three type-452 highway bridges in the state. It retains a high degree of historic physical integrity, as it retains all of its original major elements.
I-75	International Bridge	Bridge	Connects Sault Ste. Marie, MI with Sault Ste. Marie, ON	1962	2	Engineering			The International Bridge on I-75 is one of Michigan's five monumental bridges. It was designed by the firm of Steinman, Boyton, Gronquist, and London of New York and cost 20 million dollars. This bridge was an ambitious project because it crossed two navigation canals and the St. Mary's River. It also is noted for the sag between the two through arch spans, which was employed because under-bridge clearance was not a concern in that area.
I-75	Straits of Mackinac	Bridge	339 - 344	1958	2	Engineering			After several decades of planning, effort, and resistance from ferry operations, the Straits of Mackinac Bridge was the first bridge to span the 5 miles of water between the Upper and Lower Peninsula of Michigan. The bridge is one of the longest suspension bridges of its type and was the longest at the time of its formal completion in 1958. The major construction achievement of 1954 was the erection of the bridge's six principal piers, including those for the two towers, the anchorages, and the backstay spans. Enormous steel caissons were sunk into the mud under the straits and then driven to bedrock.
I-75	Sigler Road	Bridge	23	1954	4	Engineering	A, C		This structure, which maintains a high level of historical physical integrity, particularly in its retention of original guardrails, is outstanding for its length and number of spans. It is a significant early example of a concrete T-beam bridge (used for greater under-bridge clearance) in the state.
I-75	Dunbar Road	Bridge	12	1955	4	Engineering	A, C		This structure is an intact representative one of 37 concrete T-beam, elliptical arch bridges and grade separations constructed for the Detroit-Toledo Expressway by June 1956. The Detroit-Toledo Expressway was constructed as part of the state highway department's emphasis on major, long distance transportation line improvement and expressway development in the period following World War II. The state highway department first issued standard plans for concrete T-beam bridges during the 1913-1914 two-year planning period, but the design was used sparingly until the development of the Interstate Highway System in the 1950s and 1960s. The bridge retains its R-4 railings.
I-75	Conrail RR and River Raisin	Bridge	13	1955	4	Engineering	A, C		This structure was the largest constructed for the Detroit-Toledo Expressway. This bridge is significant in the state for its width, length, and large number of spans.
I-94	M-10 John C. Lodge Expressway Interchange	Bridge	215	1953	4	Engineering	A, C		The M-10/I-94 interchange is significant as the first full freeway-to-freeway interchange in the U.S. The entire interchange is included because the interface of state trunk line resources cannot be cleaved from interstate resources when assessing its historical significance. The interchange was completed prior to the I-94 designation.
MINNESOTA
I-94	Lowry Tunnel (Minneapolis)	Tunnel	232.4 - 232.7	1971	2	Engineering, Social history			The Lowry Tunnel was perhaps an early transportation solution to avoiding huge impacts to a neighborhood. Builders used an underground refrigeration system to stabilize the soils that supported the Basilica of St. Mary, Hennepin Avenue Methodist Church, and other historic structures in the area to prevent movement or damage.
I-94	Minnesota Road Research Project (Ostego)	Road bed	196.7 - 200.1	1993	2	Engineering			The Minnesota Road Research Project (Mn/ROAD) is the world's largest and most comprehensive outdoor laboratory, distinctive for its electronic sensor network embedded within 6 miles of test pavements. Located 40 miles from Minneapolis/St. Paul, its design incorporates 4,572 electronic sensors. Its network includes an extensive data collection system that provides opportunities to study how heavy commercial truck traffic and the annual freeze/thaw cycle affects pavement materials and designs. Mn/ROAD consists of two road segments that run parallel to I-94 near Otsego, Minnesota. The mainline section is a 3.5 mile stretch of interstate that carries an average of 26,400 vehicles per day. The low-volume roadway is a 2.5 mile closed loop where controlled weight and traffic volumes simulate conditions on rural roads.
I-35	Mesaba Avenue to 26th Avenue East (Duluth)	Highway Segment	256.2 - 259.6	1992	2	Social history			The project was designed to reconnect downtown Duluth to the Lake Superior waterfront while removing abandoned warehouses, rubble heaps, and rusted machinery. This was accomplished by relocating a rail yard, including five separate railroads; constructing four cut-and-cover tunnels built over a 13-block span; removal and relocation of 144,000 cubic yards of rock that created 6.3 acres of new public land along the shoreline (including the use of 10,000 cubic yards to build a 5-foot-high, 15-foot-wide, and 1,200-foot-long trout spawning reef in Lake Superior); the Lakewalk - a shoreline hike-and-bike trail extending from Lake Place to Leif Erikson Park (creating for the first time a recreational activity area along the lakefront); and a 580-foot-long Image Wall along the outside wall of Lake Place, made of 1.27 million ceramic tiles and depicting 73 different images and scenes of Lake Superior maritime activity. The tops of the tunnels were utilized to create the 2.5-acre Lake Place, recreate Leif Erikson Park and its famous rose garden (featuring the planting of over 2,000 plants of 99 different varieties), and the Jay Cooke Park. Also, the Brewery Historic District Tunnel allowed the preservation of the Fitger Brewery Complex and other historic structures. The project included ornamental fixtures, carefully selected and arranged landscaping, and an aesthetically pleasing retaining wall. Construction of the freeway was an enhancement to the Duluth inner city, reconnecting it to Lake Superior.
MISSISSIPPI
No recommended elements
MISSOURI
No recommended elements
MONTANA
No recommended elements
NEBRASKA
I-80	Overland Trail ruts at Sutherland eastbound rest area	Rest area	159.6	1968	1	Archeological, Events			Nebraska Department of Roads (NDOR) files indicate that in 1967 department engineers were cautioned to control grading operations to ensure minimum damage to the Overland Trail. Further coordination on the trail resulted in the acquisition of additional right-of-way to preserve Oregon Trail ruts. The tenant on this ground was not in sympathy with NDOR's effort and mentioned plowing up the area. The area containing the ruts was preserved and plaques identified as 'Crossing the Overland Trail' and 'The Great Platte River Road' were developed in cooperation with the Nebraska Historical Society and placed in the rest area.
I-80	Nebraska's 500 Mile Sculpture Garden	Rest area	61.37, 132.55, 193.75, 270.94, 314.93, 355.23, 381.29, 425.08	1976	2	Art, Community involvement			This sculpture project was conceived in 1973 as a project of the Nebraska American Bicentennial Commission and was dedicated in 1976. The purposes of the project were to celebrate the nation's bicentennial by providing Nebraskans and visitors access to some of the best sculptures of the time outside of museum walls and to contribute to Nebraska's cultural heritage. It also provided Nebraskans an opportunity to meet and work with the sculptors. It is known as "Nebraska's 500 Mile Sculpture Garden" because the eight works are spaced at rest areas along the state's length of I-80. The project solicited proposals nationally and selected artists represented the breadth of contemporary design in the 1970s. The project was significant for a number of reasons: (1) it was conceived at a time before the concept of placing art in public settings was an accepted norm; (2) it was ahead of its time in conceiving of a statewide project using a transportation system as its venue; and (3) it used community buy-in as a way of ensuring that the projects were successful. Sometimes controversial in the Nebraska press, the project received national acclaim.
NEVADA
No recommended elements
NEW HAMPSHIRE
I-93	Franconia Notch Parkway	Highway Segment	102.9 - 111.5	1987	2	Engineering, Transportation, Conservation, Social history			A four-lane highway extending I-93 through Franconia Notch that would meet the existing AASHTO standards would have radically altered the scenic beauty of Franconia Notch in the White Mountains, the site of the Old Man of the Mountain, a National Natural Landmark as well as the symbol of the State of New Hampshire. A special provision of the Federal-Aid Highway Act of 1973 permitted this segment of I-93 to be designed and built as a two-lane highway section. It also represents the accommodation of and access to Franconia Notch State Park recreational facilities and natural resources in the highway design and utilization of a multi-disciplinary team approach to create an early exemplar of context sensitive solutions. It remains the only two-lane highway in the entire Interstate Highway System.
I-93	Robert Prowse Memorial Bridge	Bridge	12.4	1964	2	Engineering			The Robert Prowse Bridge achieves exceptional significance under Criterion Consideration G for its innovative engineering design by NHDOT's nationally recognized engineer, Robert Prowse. Its steel rigid frame is composed of five frames or bents designed to function as a series of parallel two-hinged rigid frames. Its design utilizes steel cutting and innovative welding technology to create each frame as a sculptural shape reflecting its internal stresses and to bring together a few large structural elements. The bridge reflects the post-World War II initiative for highway bridge designers to produce connections through welding rather than riveting technology. This technology was rapidly adopted for the production of long bridge stringers, permitting the construction of continuous stringer bridges rather than utilizing built-up plate girders. Prowse verified assumptions and complex calculations by using the Beggs deformeter to test models of his structure. The bridge was the first known example of all-welded steel rigid frame technology used along the Interstate Highway System or on primary road systems in the U.S.
NEW JERSEY
I-95	George Washington Bridge	Bridge	Connects Fort Lee, NJ with Manhattan Island, NY	1931, 1963	1	Engineering			The George Washington Bridge is a suspension bridge with a 3,500-foot-long main span now carrying I-95 over the Hudson River. It was designed by Othmar Ammann, and the suspension system was built by John A. Roebling and Sons. Le Courbusier, a pioneer of the modern architecture movement, wrote: "The George Washington Bridge over the Hudson is the most beautiful bridge in the world." It has been designated an ASCE Landmark by the American Society of Civil Engineers, and its expansion received the 1963 ASCE Outstanding Civil Engineering Achievement award.
I-278	Goethals Bridge	Bridge	Connects Elizabeth, NJ with Staten Island, NY	1928	1	Engineering, Events			The Goethals Bridge was designed by J.A.L. Waddell with Othmar Ammann and was intended by the Port Authority of New York and New Jersey to alleviate the congested ferry system to Staten Island, as well as provide the first link for vehicular traffic between Staten Island and the New Jersey mainland. It was the first bridge constructed by the Port Authority of New York and New Jersey under a joint agreement to improve the port operations of both states and has an unusual 135-foot-span height to accommodate shipping traffic. The bridge, which crosses the Arthur Kill (Staten Island Sound), consists of a high 672-foot-long span formed by a cantilever steel through truss and long elevated steel girder approaches supported by concrete piers, with a total length of one mile.
I-76	Walt Whitman Bridge	Bridge	Connects Philadelphia, PA with Gloucester, NJ	1957	1	Engineering, Events			The Walt Whitman Bridge over the Delaware River is one of the last bridges designed by Othmar Ammann, who applied the design standards that characterized post World War II suspension bridges, e.g., deep stiffening trusses and streamlined towers. Firms associated with the bridge include 1) Ammann and Whitney, 2) Modjeski and Masters, 3) Bethlehem Steel, and 4) American Bridge Company/United States Steel. It was named the "Most Beautiful Structure of Steel of 1957" by the American Institute of Steel Construction. It was incorporated into the Interstate Highway System in 1956 while still under construction and became one of the first newly constructed Interstate Highway System bridges.
I-676	Ben Franklin Bridge	Bridge	Connects Philadelphia, PA with Camden, NJ	1926	1	Engineering, Events			When completed in 1926, the Camden-Philadelphia Bridge, as it was originally known, ranked as the longest suspension bridge in the world. The handsome structure, designed by Ralph Modjeski and architect Paul Certe, was the single most influential structure in the subsequent development of Camden and the surrounding area. The span remains as one of the finest and best-preserved important suspension bridges in the country and is one of Modjeski's most significant works. It carries traffic over the Delaware River.
I-78	Holland Tunnel	Tunnel	Connects Jersey City, NJ with Manhattan Island, NY	1927	1	Engineering, Transportation	A, C	Listed 11/4/1993	The Holland Tunnel was the world's first long underwater mechanically ventilated vehicular tunnel, and when it opened it was the longest underwater tunnel in the world, with its north tube 8,558 feet long and its south tube 8,371 feet long. It carries traffic under the Hudson River and is a National Historic Landmark.
I-295	Delaware Memorial Bridge (see entry under Delaware)
I-280	William A. Stickel Bridge	Bridge	14.6	1949	4	Engineering, Events	A, C		The Stickel Bridge is significant for its mechanical systems and role in transportation planning in New Jersey. The primary operational challenge of the tower-drive-type vertical lift bridge is synchronizing the independent motors located in each tower. The bridge used new amplidyne technology developed by General Electric (GE) just prior to World War II to engineer this synchronization and has retained the original electrical-mechanical equipment provided by GE. Movable bridges have been an important part of transportation planning in New Jersey due to the state's many navigable waterways in developed areas. The Stickel Bridge played a significant part in New Jersey's post-World War II transportation planning.
NEW MEXICO
I-25	Nogal Canyon Bridges	Bridge	107	1968	2	Transportation history			Nogal Canyon Bridges on I-25, between Socorro and Truth or Consequences, features two parallel Warren deck truss bridges 114.6 meters in length, soaring over Nogal Canyon. The bridges permitted the interstate to avoid the extreme grade of the canyon, bypassing the once meandering corridor of the El Camino Real and U.S. 85 highways. This segment bypasses the old highway, cutting off a historically circuitous route through what was once called "the Valley of Death", and is therefore important in the history of transportation in the state.
NEW YORK
I-95	George Washington Bridge (see entry under New Jersey)
I-87 I-287	Tappan Zee Bridge	Bridge	21 - 26	1955	1	Engineering			The Tappan Zee Bridge is significant in engineering history for its use of prefabricated buoyant caissons supports.
I-678	Bronx-Whitestone Bridge	Bridge	12 - 13	1939	1	1939 World's Fair, Tourism and recreation development, Engineering design			The Bronx-Whitestone Bridge was constructed in an astonishing 23 months to accommodate automobile traffic for the 1939 New York World's Fair in Flushing Meadow Park. Designed by Othmar Ammann, the bridge served as the gateway to the fair's "World of Tomorrow." Construction of the bridge also made the development of two major recreation areas possible: Ferry Point Park in the Bronx and Francis Lewis Park in Queens.
I-278	Goethals Bridge (see entry under New Jersey)
I-287	Triborough Bridge	Bridge	26 - 29	1936	1	Engineering			The Triborough Bridge is significant for its complex design incorporating four bridge spans and 13,500 feet of viaducts originally connecting three boroughs and two islands in New York City. The bridge also is significant for having been designed by renowned bridge engineer Othmar Ammann. It has been designated an ASCE Landmark by the American Society of Civil Engineers.
I-95	Trans-Manhattan Expressway Connector Ramp	Elevated Highway	0.5 - 0.6	1939	1	Engineering	C	Eligible 6/2003	The Trans-Manhattan Expressway Connector Ramp was determined eligible for the National Register in 2003 by the NYSDOT because it is a work of a master, has high artistic value, and demonstrates individuality or variation of features within bridge type. It was designed by Aymar Embury II and is a multi-span, concrete arch-deck with unique form-liner detail that simulates a brick appearance to the concrete. It represents a significant variation of an uncommon bridge type.
I-478	Brooklyn-Battery Tunnel	Tunnel	0 - 2	1950	1	Engineering			The Brooklyn-Battery Tunnel is the longest continuous underwater vehicular tunnel in North America and the longest continuous underwater vehicular tunnel in the world.
I-495	Queens-Midtown Tunnel	Tunnel	0 - 1	1940	1	Engineering, New Deal public works projects			The Queens-Midtown Tunnel was one of the largest public works projects of the New Deal era and represented the most advanced tunnel engineering techniques of its day.
I-190	Grand Island Bridges	Bridge	14 - 16, 21 - 22	1935	1	Engineering			The Grand Island Bridges are significant for their engineering design and as part of the New Deal era funding programs with the Niagara Frontier Authority.
I-278	Thaddeus Kosciusko Bridge	Bridge	21 - 22	1939	1	Engineering design, Commemoration of the American Revolution			The Thaddeus Kosciusko Bridge is significant for its unique design combining a through truss spanning 5,536 feet with 103-foot-long support spans linking Brooklyn and Queens. The bridge is named in honor of Thaddeus Kosciusko, a Polish general in the American Revolutionary War. Two of the bridge towers are surmounted with a Polish eagle and an American eagle.
I-90	Route 64 Bridge over I-90	Bridge	27 - 28	1952	1	Engineering			The Route 64 Bridge is significant as an unusual example of reinforced concrete arch construction on the NY State Thruway system.
I-190	Queenston-Lewiston Bridge	Bridge	Connects Lewiston, NY with Queenston, ON	1965	2	Engineering			The Queenston-Lewiston Bridge, which crosses the Niagara River, was the longest fixed-end steel arch bridge in the world at the time of construction. It is the fourth busiest border crossing between the U.S. and Canada.
I-278	Verrazano Narrows Bridge	Bridge	8 - 10	1964	2	Engineering			Designed by Othmar Ammann, the Verrazano Narrows Bridge was the world's longest suspension bridge at the time it was completed. It received the 1965 Outstanding Civil Engineering Achievement award from the American Society of Civil Engineers.
I-81	Barge Canal Bridge	Bridge	100 - 103	1959	2	Engineering			The I-81 Bridge crossing Oneida Lake in Onondaga County is significant as the longest post-tensioned concrete bridge in the western hemisphere at the time of completion.
I-495	Long Island Expressway Viaduct	Bridge	3 - 4	1940, 1969	2	Engineering			The Long Island Expressway Viaduct spans 3,856 feet from Maspeth Avenue to the Brooklyn-Queens Expressway. The bridge was originally constructed at grade (1940) and later rebuilt (1969) as a double deck structure due to space constraints, in particular an adjacent cemetery.
I-295	Grand Central Parkway Interchange	Highway Segment	0 - 0.4	1963	2	Engineering			This four-layered, cantilevered interchange is significant as a one-of-a-kind structure for New York City and a possible precedent-setting design for the Interstate Highway System as a whole.
I-78	Holland Tunnel (see entry under New Jersey)
I-278	Brooklyn-Queens Expressway Esplanade	Highway Segment	16 - 17	1954	3	Engineering	A, C	Listed 1/12/1965	This 8-block, 3-level cantilevered structure is significant as an innovative solution for constructing a modern highway while preserving the integrity of Brooklyn Heights neighborhood and preserving area views of Manhattan. The esplanade contributes to the Brooklyn Heights National Historic Landmark District.
I-87	Major Deegan Expressway	Highway Segment	0 - 9	1956	4	Engineering			The Major Deegan Expressway, later incorporated in the Interstate Highway System, is unique for its "parkway" elements consisting of stone walls, bridges, parks, and the Albany Crescent.
I-278	Brooklyn Queens Expressway Corridor	Highway Segment	17 - 22	1950	4	Engineering, Social history			Running between Brooklyn Heights and the Thaddeus Kosciusko Bridge, this corridor along the Brooklyn-Queens Expressway is significant for the design of its bridges, roadside features, and park development. The Brooklyn-Queens Expressway contains a unique collection of Art Deco-style, multi-flange beam and column capped bridges and stone or brick-lined retaining walls. Robert Moses mitigated the impact of the expressway by building small neighborhood parks in vacant spaces left by buildings demolished for roadway construction and using brick facing on concrete abutments in an attempt to blend the expressway into the urban landscape.
I-95	Cross Bronx Expressway Corridor	Highway Segment	0 - 7	1955	4	Engineering, Social history			The Cross Bronx Expressway is significant for its association with the public works programs of Robert Moses, the substantial engineering challenge of putting a major expressway through a dense urban neighborhood surmounted by the project, and the use of innovative mitigation measures for the neighborhood expressway. The corridor consists of stone-lined cut sections, tunnels, and viaducts to accommodate natural and man-made features, and has many pedestrian overpasses and underpasses. The edges of the expressway are lined with playgrounds, malls, and parks to buffer the highway from the surrounding neighborhoods.
I-278	Gowanus Expressway Viaduct	Bridge	11 - 15	1941	4	Engineering, Social history			The Gowanus Expressway Viaduct, running for 18,472 feet from 65th Street to the Prospect Expressway, is significant as a massive cantilevered roadway adaptively reused from an original 1941 elevated subway and widened in 1961 to accommodate six lanes while retaining the original subway supports. It also is important for local history in the changing planning paradigms in favor of the automobile with the road construction dividing neighborhoods on a large scale.
NORTH CAROLINA
I-240	Great Smoky Mountain Park Bridge	Bridge	4	1950	4	Engineering	C	Eligible 3/2003	The Great Smoky Mountain Park Bridge was one of the NC State Highway Commission's earliest, high-profile urban bridge projects in the post World War II era. At the time of its construction, the bridge was one of the longest applications of continuous design principles yet attempted by the state bridge unit. It was one of the largest and most technically challenging projects taken on by the unit's engineers during the period. The Great Smoky Mountain Park Bridge is the only Art Moderne style highway bridge dating to before 1961 in North Carolina.
NORTH DAKOTA
No recommended elements
OHIO
I-80	Cuyahoga River Bridges	Bridge	176.9	1999	2	Engineering, Aesthetics			The Ohio Turnpike's set of bridges over the Cuyahoga River is a pair of 2,664-foot long bridges. The bridges span the Cuyahoga River Valley with a contextual design to match the historic features of the valley including the towpath.
I-70	Welcome to Ohio Arch	Structure	0.2	1968	2	Aesthetics, Communication			The Welcome to Ohio Arch is a steel arch that spans I-70 at the Ohio/Indiana State Line. This structure was constructed in 1968. The structure was designed to carry welcome and departure signs. This structure was intended to be one of 10 similar structures to be placed at the state lines. However, due to public opposition and funding issues, this is the only one that was constructed.
OKLAHOMA
I-44	Glass House Restaurant	Rest Area	288	1957	2	Architecture			The Glass House Restaurant structure actually spans the Will Rogers Turnpike (I-44) and may be accessed by patrons traveling in either direction. Originally built by Conoco, it is owned by the Turnpike Authority and leased to the concession. Several sources indicate that it was the first restaurant facility constructed over a public highway in the U.S., and that it was considered the largest McDonalds restaurant in the world until recently surpassed by those in Moscow, Peking, and Orlando. Overhead restaurants are a rare property type found on the Interstate Highway System, and the Glass House Restaurant is an excellent example of roadside architecture designed in the Late Modern style. Character defining features include: vertical sunshade louvers on one side, natural stone facing, large glass curtain wall construction, and a concrete arch structure for the central span and roof.
OREGON
I-84	Historic Columbia River Highway	Highway Segment	22 - 82	1922	1, 3	Engineering	A, C	Listed 12/12/1983	The Historic Columbia River Highway is a National Register listed resource and has been designated an ASCE Landmark by the American Society of Civil Engineers. It includes multiple structures and corridors that wind in and out of the I-84 right-of-way. Portions also are designated as a National Historic Landmark.
I-84	Toothrock Tunnel	Tunnel	41.3	1937	1	Engineering	A, C	Listed 12/12/1983	The Toothrock Tunnel is part of the Historic Columbia River Highway National Historic Landmark.
I-405	Fremont Bridge	Bridge	3.3	1973	2	Engineering			The Fremont Bridge is eligible under Criteria Consideration G. It is a stiffened steel tied arch with an orthotropic upper deck. When constructed in 1973, the 902-foot long main span was floated into place on the river and hydraulically lifted 170 feet into place, making it the largest lift ever made. It also features the longest single span length in the state.
I-5	Columbia River Bridge (northbound)	Bridge	Connects Portland, OR with Vancouver, WA	1917	3	Engineering	A, C	Listed 7/16/1982	The Columbia River Bridge (northbound) was a major engineering and financial accomplishment, being the first highway bridge across the Columbia River to connect Oregon and Washington. The main span is a through truss vertical lift designed by Harrington, Howard, and Ash. The 10 spans of the bridge range in length from 266 to 531 feet and are of the Pennsylvania-Petit type. This is one of a pair of bridges crossing the Columbia River on 1-5 connecting Vancouver, Washington, and Portland, Oregon, that are significant for their engineering. The second bridge, which now carries southbound traffic, was built on the west side of the original span in 1958.
I-82	Columbia River Bridge (Umatilla) (eastbound)	Bridge	0.4	1955	4	Engineering	C	Eligible 1/25/2001	The Columbia River Bridge at Umatilla (eastbound) is a five-span continuous Warren through truss design. The configuration of the span is unusual in the fact that it takes advantage of a submerged island near the middle of the Columbia River. With its two 600-foot spans, each constructed using the cantilever method, this is the only bridge in the state having two spans constructed using that method.
I-84	Sandy River Bridge (eastbound)	Bridge	17.7	1949	4	Engineering	C	Eligible 5/18/2005	The Sandy River Bridge (eastbound) is significant as a representative example of its type from this era.
I-84	Jordan Road Bridge (eastbound)	Bridge	17.8	1946	4	Engineering	C	Eligible 5/18/2005	The Jordan Road Bridge (eastbound) is significant as a representative example of its type from this era.
I-84	Jordan Road Bridge (westbound)	Bridge	17.8	1946	4	Engineering	C	Eligible 5/18/2005	The Jordan Road Bridge (westbound) is significant as a representative example of its type from this era.
PENNSYLVANIA
I-376	Penn Lincoln Parkway - East	Highway Segment	3 - 10	1953	1	Transportation, Engineering			The Penn Lincoln Parkway - East, based upon the plans of Robert Moses, was constructed between 1946 and 1953. When dedicated on June 5, 1953, the parkway extended from U.S. 22 at Churchill to Bates Street, in Pittsburgh. The first modern expressway in the Pittsburgh area, the Penn Lincoln Parkway - East encompassed significant planning and integration with existing transportation systems, while attempting to limit dislocation of existing development and incorporate scenic viewsheds and landscape elements.
I-70 I-76	Pennsylvania Turnpike, Carlisle to Irwin	Highway Segment	67 - 226	1940	1	Transportation, Government, Engineering			The Pennsylvania Turnpike was constructed between 1938 and 1940 along the abandoned right-of-way of the South Penn Railroad and is recognized for the engineering standards utilized in its design and construction. The Pennsylvania Turnpike was the first long distance, high speed, limited access superhighway in the U.S. The Pennsylvania Turnpike also is recognized for its financing system, which became the model for subsequent toll road construction. In addition, the turnpike was a significant New Deal era public works project in Pennsylvania.
I-76	Walt Whitman Bridge (see entry under New Jersey)
I-676	Ben Franklin Bridge (see entry under New Jersey)
I-279	Fort Pitt Bridge and Tunnel	Bridge, Tunnel	5 - 6	1959, 1960	2	Engineering			TheFort Pitt Bridge was designed by George S. Richardson and was constructed between 1956 and 1959. The Fort Pitt Bridge is recognized as the world's first double deck, tied bow truss bridge. The Fort Pitt Tunnel was constructed between 1957 and 1960 and was a vital link on the Penn Lincoln Parkway, along with the Fort Pitt Bridge. The tunnel and bridge are noted as innovative solutions to complex engineering obstacles.
RHODE ISLAND
I-195	Washington Bridge	Bridge	1.6 - 1.8	1930	3	Transportation, Engineering	A, C	Eligible 1989	The Washington Bridge is a Classical Revival style, 12-span open-spandrel concrete arch structure with a masonry façade constructed in 1930. It has a span length of 1,864 feet and it carries I-195 eastbound traffic over the Seekonk River in the City of Providence and the Town of East Providence, Rhode Island. The structure is of state-level significance and was determined eligible for listing in the National Register by the Keeper of the National Register as part of the Rhode Island Historic Bridge Inventory Thematic Nomination in 1989.
SOUTH CAROLINA
No recommended elements
SOUTH DAKOTA
I-90 I-29	Tipi Structure	Structure in rest area	I-90: 1, 98/99, 264, 362/363, 412 I-29: 26, 250	1968	2	Cultural, Aesthetic value			Large concrete tipi structures mark rest areas along I-90 and I-29. South Dakota architect Ward Whitwam, FAIA (Fellow of the American Institute of Architects), designed these tipi structures in the 1960s. The first two were constructed in the late 1960s at rest areas near Salem and Wasta. The remaining tipi structures were constructed in the 1970s. The tipi structures are found along I-90 at the Northern Hills Rest Area, Cheyenne River Rest Area, Lewis and Clark Rest Area, and Valley Springs Rest Area. The tipi structures along I-29 are found at the Homestead Rest Area and the Glacial Lakes Rest Area. These distinctive tipi structures are unique to South Dakota.
TENNESSEE
I-40	Hernando DeSoto Bridge (see entry under Arkansas)
I-55	Memphis and Arkansas Bridge (see entry under Arkansas)
TEXAS
I-40	Bridge 25-242-0275-13-001	Bridge	171	1932	4	Engineering	C		The I-40 frontage road bridge is located on the alignment of US 66 in Wheeler County. The bridge crosses the former roadbed of the I & G Railroad. The bridge is significant for its type and railing. It is one of only a few known examples of a bridge in Texas with a concrete encased steel I-beam configuration and is noteworthy for its Type D railing.
I-10	Bridge 06-186-0140-03-021	Bridge	291	1933	4	Engineering	C		The I-10 frontage road bridge over Tunis Creek in Pecos County is a good example of a standard plan reinforced concrete girder bridge designed by the Texas State Highway Department in the 1930s. The bridge is one of the longest examples of its type in the state.
I-35	Bridge 09-014-0015-06-055	Bridge	290	1935	4	Engineering	C		The I-35 frontage road bridge over the Lampasas River in Bell County is significant as a distinctive example of fabricated girder construction. The bridge represents an innovative design response to a difficult site crossing and is one of only three known examples of a two-girder span configuration in Texas.
I-35	Bridge 22-142-0017-08-030	Bridge	79	1929	4	Engineering	C		The I-35 frontage road bridge over Cibolo Creek in LaSalle County is a good example of an early State Highway Department standard plan concrete girder bridge. It is one of the longest (99 feet) examples of its type and period.
I-20	Bridge 23-068-0314-05-018	Bridge	364	1934	4	Engineering	C		The I-20 North frontage road bridge over the south fork of Palo Pinto Creek is located in Eastland County. It is a good representative of State Highway Department design in the 1930s. The bridge's combination concrete girder and steel superstructure system and solid panel approach walls distinguish this bridge from other standard design structures of the period.
I-20	Bridge 23-068-0314-05-020	Bridge	363	1934	4	Engineering	C		The I-20 South frontage road bridge over Bear Creek in Eastland County is a good representation of a reinforced concrete girder bridge designed by the State Highway Department in the 1930s. The bridge is principally distinguished for its curved concrete approach walls.
UTAH
No recommended elements
VERMONT
I-91	Historic Crown Point Road	Underpass	42.6	1965	1	Transportation, Engineering			The Crown Point Road pedestrian underpasses on I-91 were constructed in 1965 to commemorate and protect the location of a historic military road, which is of corduroy construction at this location. Underpasses go under both northbound and southbound lanes, which are separated by wide median. The Crown Point Road was considered a major engineering feat when first constructed in 1759-60 by General Amherst for transporting troops and supplies to the shores of Lake Champlain to fight the French/Indians. The SHPO is reviewing a MPDF for the military road which has dates ranging from 1759 to 1779.
I-89	Vietnam Veteran's Rest Area	Rest area/ Memorial/ Museum	8.8	2005	2	Architecture, Culture, Social history (memorial)			Since October 30, 1982, a memorial to Vermont Vietnam Veterans has existed here, where veterans meet and hand out coffee and refreshments to travelers and educate the public. One exit south is the White River Jct. Veterans Hospital. In 1990s veterans were able to stop the closing of this rest area when many others were closed. In 2005, a new rest area was opened to memorialize veterans and the war in a more permanent way. Tim Smith of Timothy Smith Associates of Bennington, Vermont, did the design work so the architecture, landscaping, and even the grasses for the living greenhouse septic treatment system are native to southeast Asia. The rest area has a museum to the Vietnam War and memorials inside and outside. The unique architecture, layout, self-contained brown water system, and continuous utilization of this location by Vietnam Veterans is nationally important for a significant sub-group of American society and is an ideal symbol of American Culture and Values.
I-91	Steel Rigid-Frame Bridge	Bridge	138.7	1970	2	Engineering			This type of bridge is very rare on interstates in New England. In Vermont, two are on I-91; one each on northbound and southbound lanes carrying the interstate over Rte. 9 in Lyndon, Vermont. As of inspection on 01/12/05, structurally both bridges are in very good condition. Engineering-wise, this style was an experiment in 1960 and 1970 to determine if steel construction could take the variable weight loadings of an interstate environment. It was designed by a New York City firm, Blauvelt Engineering Co., and received a merit award from the American Institute of Steel Construction in 1974. The overall length of the bridges is 227 feet, 6 inches.
VIRGINIA
No recommended elements
WASHINGTON
I-90	Mount Baker Ridge Tunnels	Tunnel	3.8	1940, 1993	1, 3	Engineering, Architecture	D	Listed 7/16/1982	The structure is exceptional in engineering for both the material it was driven through (unstable clay) and the form it took (twin bore). The tunnel ranks as the world's largest diameter soft earth tunnel. It was part of the Lake Washington Floating Bridge/Lacey V. Murrow Memorial Bridge project. The tunnel portals feature a striking modernistic style. The twin bores are 1,440 feet in length and were rehabilitated in 1993. They are included in the Historic American Engineering Record (HAER No. WA-109). Note that in its National Register listing, the NRIS incorrectly identifies its location as east of 'WA 90', instead of 'I-90'.
I-90	Lake Keechelus Snowshed Bridge	Snowshed bridge	58	1951	1, 3	Engineering	A, C	Listed 5/24/1995	The Lake Keechelus Snowshed Bridge is listed on the National Register as part of the Bridges of Washington State Multiple Property Submission. It also is included in the Historic American Engineering Record (HAER No. WA-110.)
I-5	Lake Washington Ship Canal Bridge	Bridge	169.6	1962	2	Engineering, Social history			The Lake Washington Ship Canal Bridge crossing Lake Washington was completed in 1962 and essentially served as the world's largest elevated parking lot when the World's Fair came to Seattle in 1962 (a.k.a., Century 21 Exposition). Ultimately, it was not used for the fair because the feeling was it would take away customers from downtown Seattle. It had a lower level, through truss, and deck truss. In terms of engineering, it was the first bridge to use computers in its design. The giant 4,429-foot bridge was completed in the fall of 1961; at the time, the largest ever built in the Northwest. It is a Warren steel truss double-deck bridge, which carries eight lanes of traffic on the upper deck and four reversible lanes of traffic on the lower deck.
I-90	Snoqualmie Pass West	Highway Segment	50 - 51.5	1971-1981	2	Engineering, Environmental issues			This interstate corridor was designed within some of the most stringent environmental requirements in the country and contains some of the most innovative structures on the Interstate Highway System. Environmental requirements resulted in an elevated roadway constructed with minimal disruption to the forest. The Denny Creek Viaduct consists of a 3,620-foot-long post-tensioned segmented concrete box-girder bridge west of Snoqualmie Pass, which is significant for its engineering and design compatibility with its mountainous setting. The structure was the first concrete box girder in Washington designed to allow access to the interior of the box girder, where specially designed bearings and seismic restrainers are situated. The 700-foot-long Franklin Falls Bridge, a steel-girder structure, is supported by the first piers in the state designed to deflect and withstand avalanches. Its unpainted steel girders were the first "weathering" girders used in the state for the purpose of blending the bridge into its natural surroundings.
I-82	Fred G. Redmon Bridge	Bridge	23.9 - 24.1	1969	2	Engineering			The Fred G. Redmon Bridge on I-82 over Selah Creek between Ellensburg and Yakima was built in 1971 and is significant for its engineering. At the time it was constructed in 1971, the twin-arch bridge was the longest concrete arch bridge in North America. Together, the two arches form the highest bridge in the state of Washington. The bridge is 1,337 feet long and rises 325 feet above the canyon floor. The arch spans (excluding approach spans) are 549 feet long.
I-82	Columbia River Bridge (Umatilla) (westbound)	Bridge	132.3	1987	2	Engineering			The newer I-82 bridge over the Columbia River at Umatilla (companion to the 1955 Umatilla bridge) was built in 1987 and is exceptionally important in the area of engineering. This second bridge was completed adjacent and east of the 1955 bridge. Today, the newer bridge carries all westbound traffic while the 1955 bridge carries eastbound lanes. It is a cantilevered concrete box with two main spans.
I-5	Freeway Park	Park	165.7	1976	2	Landscape Architecture, Social History			Freeway Park on I-5, Seattle is a park built partially over the Interstate to utilize and reconnect the landscape at the Convention Center. It was built between 1972 and 1976 and was designed by Lawrence Halprin, an important landscape architect of the 20th century. It is a 5-acre park built on an overpass above I-5 between Seneca and University Streets. Halprin designed waterfalls and fountains to mute the noise of the eight-lane freeway below, and it re-established a pedestrian connection between neighborhoods that were bifurcated when I-5 was built in the 1960s.
I-90	Columbia River Bridge (Vantage)	Bridge	137	1962	2	Engineering			The Columbia River Bridge at Vantage is important for its engineering, reflected in its four-lane, 520-foot steel through-arch. Its steel-girder and Warren deck-truss approach spans bring the structure's total length to 2,504 feet. Since completed, the bridge has provided a vital regional link in the Interstate Highway System. Its graceful tied arch design, with predominant parabolic top chord, was an unusually sensitive, aesthetically appropriate response to the dramatic landscape of surrounding mountains. Its color scheme, painted a sandy tan, matches the desert environment, also unusual for the times. Built in 1962, the bridge could be viewed as an early response to what would become generally known as the "Environmental Movement."
I-90	Lake Washington	Highway Segment	3.4 - 8.9	1992	2	Engineering, Social history			This segment includes LIDs, tunnels, concrete floating pontoon bridges, and concrete box girder bridges connecting Seattle with Mercer Island and communities east of Lake Washington. Significant features include: 1) the Lacey V. Murrow Memorial Bridge, which is a floating concrete-pontoon bridge that is 8,981 feet long and carries the eastbound lanes of I-90 across Lake Washington (the original two-way, four-lane toll bridge, built in 1940, was the first floating reinforced concrete pontoon bridge in the world; however, it sank in a storm on November 25, 1990, while it was undergoing repair); 2) the Homer M. Hadley Memorial Bridge, which is a floating concrete-pontoon bridge that is 9,559 feet long and carries the westbound lanes of I-90 across Lake Washington; 3) the twin Mount Baker Ridge Tunnels (see previous entry); 4) the Luther Burbank LID, which is a landscaped park over the interstate; and 5) the East Channel - Lake Washington Bridges, which are concrete continuous box girder and beam structures connecting Mercer Island with the eastern lake shore communities.
I-5	Olympia Freeway	Highway Segment	104.2 - 109.2	1988	2	Engineering, Social history			This segment of I-5 contains several award-winning bridges, most notably the Capitol Blvd. Undercrossing, which converted a 1956 pier-supported deck to an elegant deck arch (1989 and 1990 awards from the National Society of Professional Engineers, American Institute of Steel Construction, and the James F. Lincoln Arc Welding Foundation). Also in this segment is the Sleater Kinney Undercrossing (1989 winner of an award from the Prestressed Concrete Institute) and the Boulevard Road Undercrossing (a precedent-setting winner of the Washington Precast Concrete Industry's Award for Excellence in 1987). The other bridges, sign bridges, lighting, sound walls, and landscaping also are important design components.
I-5	Toutle River Bridges	Bridge	51.7	1969	2	Engineering, Social history			Slightly offset due to their skewed crossing of the Toutle River, these two matching steel through-arches are the only ones of their type in Washington. Vertical ties are complemented by diagonal tension members, with overhead cross-lateral bracing. The resulting design is one of exceptional aesthetic quality. Surviving Mount St. Helen's eruption debris flows carrying houses, trees, and other large objects, the bridges underwent structural modifications anticipating future cataclysmic events. The structures remain significant for their association with the 1980 eruption of Mount St. Helens.
I-705	Tacoma Downtown	Highway Segment	0.3 - 1.1	1988, 2003	2	Engineering, Social history			Construction of I-705 in 1987-1988, providing access from I-5 to downtown Tacoma and Schuster Parkway beyond, was a critical element in the cultural and economic revitalization of the city's urban commercial and industrial centers. Consisting of 12 elevated structures comprised primarily of post-tensioned concrete box girders, the interstate and numerous sweeping overcrossings and undercrossings stand in dynamic contrast to the dense concentration of historic-era buildings along adjacent city streets. The crown jewel of this segment is the 2003 Chihuly Bridge of Glass, a steel girder structure supporting stacked cases of glass sculptures by the renowned artist Dale Chihuly, a Tacoma native. His blue "Ice" sculptures rise high above the bridge deck, clearly visible to the drivers on I-705 below, reminding visitors of the bridge's role in connecting the recently constructed Museum of Glass in the revitalized industrial waterfront with the modern Washington State History Museum, University of Washington-Tacoma campus, and nearby commercial district.
I-5	Columbia River Bridge (northbound) (see entry under Oregon)
I-82	Columbia River Bridge (Umatilla) (eastbound) (see entry under Oregon)
WASHINGTON, DC
No recommended elements
WEST VIRGINIA
I-70	Fort Henry Bridge	Bridge	0.4	1955	4	Engineering, Transportation	A, C		Opened to traffic with fanfare in September 1955, the Fort Henry Bridge is a tied-arch design with a main span of 580 feet. Built at a cost of $6,800,000, the bridge represented a great leap forward for road transportation in the Wheeling area. It was part of a larger transportation plan for US 40 prepared by the engineering firm of Howard, Needles, Tammen, and Bergendoff. At the time of construction, the bridge was only the second tied arch over the Ohio River.
I-64 I-77	Yeager Bridge (southbound)	Bridge	94.5	1954	4	Engineering, Transportation	A, C		The Yeager Bridge, at 2,167 total feet in length, is a tied-arch design carrying the West Virginia Turnpike over the Kanawha River. Designed by Howard, Needles, Tammen, and Bergendoff in 1952, the bridge opened to traffic in 1954. There were 76 bridges along the original 88 miles of the turnpike between Charleston and Princeton.
I-77	Charlton Bridge (southbound)	Bridge	17.5	1954	4	Engineering, Transportation	A, C		Built to carry the West Virginia Turnpike over the gorge of the Bluestone River, the Charlton Bridge is a deck truss design spanning 1,342 feet. Built to the designs of Howard, Needles, Tammen, and Bergendoff, the bridge bears the name of posthumous Medal of Honor recipient Cornelius C. Charlton. The turnpike's major bridges were all named after modern military heroes.
WISCONSIN
No recommended elements
WYOMING
I-80	Lincoln Statue	Sculpture in rest area	337	1959, 1969	2	Art			The Lincoln Monument at the I-80 summit lies southeast of Laramie and west of Cheyenne on I-80 at the edge of a rest area. It stands at a summit near Sherman Hill and marks the highest point on I-80, about 8,640 feet above sea level. It was originally commissioned in 1959 and was placed along the Lincoln Transcontinental Highway. It was moved to its present site in 1969 when I-80 was constructed. The bronze bust of Abraham Lincoln was sculpted by Robert Russin and is 12.5-feet high atop a 30-foot tall granite pedestal. The artwork represents Lincoln's determination to create dependable transcontinental transportation and the difficulties inherent in crossing the Continental Divide. It is exceptionally significant because it is one of the few pieces of art along the entire Interstate Highway System.

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