Concurrency (road)
Videos
A concurrency in a road network is an instance of one physical roadway bearing two or more different route numbers. When two roadways share the same right-of-way, it is sometimes called a common section or commons. Other terminology for a concurrency includes overlap, coincidence, duplex, triplex, multiplex, dual routing or triple routing.
An extreme example: I-40, I-85 Business, US 29, US 70, US 220, and US 421 formerly ran concurrently in Greensboro, North Carolina. In 2008, I-40 was rerouted off this road but was put back on it later that same year with US 220 being rerouted instead. US 421 was also rerouted in 2009.
The Queen Elizabeth Way concurrent with Highway 403 in Ontario
A section of Ontario Highway 400 runs concurrent with a branch of the Trans-Canada Highway.
Concurrency of the city beltway, a European road, and three first-class roads in Hradec Králové, Czech Republic
Interstate 39
Videos
Interstate 39 (I-39) is a highway in the Midwestern United States. I-39 runs from Normal, Illinois, at I-55 to State Trunk Highway 29 (WIS 29) in the town of Rib Mountain, Wisconsin, which is approximately six miles (9.7 km) south of Wausau. I-39 was designed to replace U.S. Route 51 (US 51), which, in the early 1980s, was one of the busiest two-lane highways in the United States. I-39 was built in the 1980s and 1990s.
I-39/US 51 in northern Wisconsin
Northern terminus of I-39 at the interchange with WIS 29 near Wausau