A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide valley, road, river, or other low-lying terrain features and obstacles. The term viaduct is derived from the Latin via meaning "road", and ducere meaning "to lead". It is a 19th-century derivation from an analogy with ancient Roman aqueducts. Like the Roman aqueducts, many early viaducts comprised a series of arches of roughly equal length.
Michigan Avenue is a north-south street in Chicago that runs at 100 east on the Chicago grid. The northern end of the street is at DuSable Lake Shore Drive on the shore of Lake Michigan in the Gold Coast Historic District. The street's southern terminus is at Sibley Boulevard in the southern suburb of Dolton, but like many other Chicago streets, it exists in several disjointed segments.
Lake Shore Drive is a semi-limited access expressway that runs alongside the shoreline of Lake Michigan and its adjacent parkland and beaches in Chicago, Illinois. Except for the portion north of Foster Avenue, the Drive is designated part of U.S. Highway 41. A portion of the highway on the Outer Drive Bridge and its bridge approaches is multilevel.
The Ship Canal Bridge is a double-deck steel truss bridge that carries Interstate 5 (I-5) over Seattle's Portage Bay between Capitol Hill and the University District. The canal below connects Lake Union with Lake Washington. Construction was completed in 1961 and the bridge opened to traffic on December 18, 1962. It is 4,429 ft long, stands 182 feet above the canal and is 119 feet wide at the upper deck. It was the largest bridge of its kind in the Northwest when it first opened. The bridge is double-decked, with the upper deck carrying traffic in both directions and the lower deck carrying traffic southbound in the morning and northbound in the afternoon.
Wacker Drive is a major multilevel street in Chicago, Illinois, running along the south side of the main branch and the east side of the south branch of the Chicago River in the Loop. The vast majority of the street is double-decked; the upper level is intended for regular street-level traffic, and the lower level for service vehicles, deliveries, waste collection, utility access, and through traffic. It is sometimes cited as a precursor to the freeway, though when it was built, the idea was that pleasure vehicles would use the upper level. Since it follows the curving path of the Chicago River, Lower Wacker Drive is the only street in the city that adopts both North–South and East–West designations. In certain areas, there is a third level of Wacker Drive, often known as Lower Lower Wacker Drive or Sub-Lower Wacker Drive. This additional layer is primarily used for towing and impounding vehicles, utility infrastructure, and rail access in some areas. The street is named after early 20th-century Chicago businessman and city planner Charles H. Wacker.
Downtown Chicago, Illinois, has some double-decked and a few triple-decked streets immediately north and south of the Main Branch and immediately east of the South Branch of the Chicago River. The most famous and longest of these is Wacker Drive, which replaced the South Water Street Market upon its 1926 completion. The resulting bi-level street has an upper-level riverfront boulevard, a lower-level roadway for commercial and through traffic, and a recreational walkway at water level.
Columbus Drive is a north–south street in Chicago, Illinois, which bisects Grant Park. It is 300 East in Chicago's street numbering system. Its south end is an interchange with Lake Shore Drive at Soldier Field. After intersecting Illinois Street, it becomes Fairbanks Court and continues to the north, terminating at Chicago Avenue.
The DuSable Bridge is a bascule bridge that carries Michigan Avenue across the main stem of the Chicago River in downtown Chicago, Illinois, United States. The bridge was proposed in the early 20th century as part of a plan to link Grant Park (downtown) and Lincoln Park (uptown) with a grand boulevard. Construction of the bridge started in 1918, it opened to traffic in 1920, and decorative work was completed in 1928. The bridge provides passage for vehicles and pedestrians on two levels. An example of a fixed trunnion bascule bridge, it may be raised to allow tall ships and boats to pass underneath. The bridge is included in the Michigan–Wacker Historic District and has been designated as a Chicago Landmark.
The Government Bridge or Arsenal Bridge spans the Mississippi River, connecting Rock Island, Illinois and Davenport, Iowa. The Iowa Interstate Railroad uses the upper deck of the bridge for its ex-Chicago and Rock Island Railroad route between Council Bluffs, Iowa and Chicago, Illinois. The lower deck carries automobile traffic between the two cities. It is located near Upper Mississippi Mile Marker 483, adjacent to the Mississippi River Lock and Dam No. 15. The current structure is the fourth at this location. The bridges all were built with a swing section to accommodate traffic navigating the river.
The Wells Street Bridge is a bascule bridge over the Chicago River, in downtown Chicago, Illinois, United States, which was built in 1922. Standing east of the Franklin Street Bridge and southeast of the Merchandise Mart, the bridge connects the Near North Side with "The Loop". The bridge is double-decked, the lower deck carrying three lanes of traffic south over the river with sidewalks on both sides of the street. The upper deck serves as a bridge for the Chicago Transit Authority's Brown and Purple lines. Bridge tenders' houses for controlling the bridge are on the northwest and southeast corners of the bridge.
The Lamar Boulevard Bridge is a historic arch bridge carrying Texas State Highway Loop 343 over Lady Bird Lake in downtown Austin, Texas, United States. The bridge features six open-spandrel concrete arches spanning 659 feet (201 m) and carries tens of thousands of vehicles daily across the lake. Completed in 1942, the Lamar Boulevard Bridge was the second permanent bridge to cross the Colorado River, and one of the last Art Deco-style open-spandrel concrete arch bridges built in Texas. The bridge was named an Austin Landmark in 1993 and added to the National Register of Historic Places in 1994.
The Park Street Bridge is a double-leaf bascule drawbridge spanning 372 feet of the Oakland Estuary in the San Francisco Bay Area. It links the cities of Oakland and Alameda. In a year, the bridge is opened approximately 1700 times and carries approximately 40,000 vehicles per work day. It was built when the Oakland Estuary was trenched, converting Alameda from a peninsula to an island.
The Pit River Bridge is a double deck, deck truss, road and rail bridge over Shasta Lake in Shasta County, California. The bridge, carrying Interstate 5 on its upper deck and Union Pacific Railroad on its lower deck, was built in 1942 as part of the construction of the Shasta Dam/Shasta Lake reservoir system. The Pit River Bridge was constructed to replace the Lower Pit River Bridge, as the rising waters of the Shasta Lake reservoir would have put the older bridge underwater. The entire bridge spans 3,588 feet (1,094 m) long on the upper deck and 2,754 feet (839 m) on the lower deck. With a height of 500 feet (150 m) above the old Pit River bed, it is structurally the highest double decked bridge in the United States; however, today the bridge sits only about 40 feet (12 m) above the water when Shasta Lake is full. The bridge is Interstate 5's halfway point.
The Taunton Tramway was an electric street tramway in Taunton, the county town of Somerset, England. It operated a fleet of six narrow gauge tramcars on a single route of 1.66 miles (2.67 km) between 1901 and 1921 when the tramway closed due to a dispute over the cost of electricity.
The Outer Drive Bridge, also known as the Link Bridge, is a double-deck bascule bridge carrying DuSable Lake Shore Drive across the Chicago River in Chicago, Illinois, United States. Construction was started in 1929 and was completed in 1937 as one of the Public Works Administration's infrastructure projects in Chicago. Completion of the bridge tied the north and south sections of the "outer" shore roadway, now called DuSable Lake Shore Drive, together. The bridge was officially named the Franklin Delano Roosevelt Memorial Bridge in 1982 to honor the centennial anniversary of the birth of Franklin Delano Roosevelt. It was planned by the Chicago Plan Commission, using Hugh E. Young as the consulting engineer, was designed by the Strauss Engineering Company, built by the American Bridge Company, and erected by Ketler and Elliot Company. It crosses near the mouth of the Chicago River.
The Carlton Bridge is a railroad vertical-lift bridge which carries one rail line over the Kennebec River between Bath and Woolwich, Maine. It was completed in 1927. Until August 1, 2000, it also carried two lanes of U.S. Route 1 (US 1) on its upper deck, after which the highway was transferred to the adjoining Sagadahoc Bridge and the road connection severed at the west end. The east end is gated, and is accessible only by authorized vehicles. The majority of the road deck remains but may be removed in the future. It is the last downstream fixed crossing of the Kennebec.
The James D. Pfluger Pedestrian and Bicycle Bridge is a shared use bridge for pedestrians and cyclists spanning Lady Bird Lake in downtown Austin, Texas. Opened in 2001, the bridge connects the north and south sides of the Ann and Roy Butler Hike-and-Bike Trail and features an unusual "double curve" design. The bridge runs parallel to the Lamar Boulevard Bridge, which carries road traffic across the lake roughly 200 feet (61 m) to the west.
