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Controlled-access highway

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Controlled-access highways are special roads built for fast travel.

Highway 401 Night Lapse Busy
Highway 401 Night Lapse Busy

People use different names for them. You might hear them called freeways, motorways, or expressways. These roads are made to keep traffic moving smoothly. They are designed to carry many vehicles at high speeds. This helps people travel between cities or through large cities quickly. They are very important for moving people and goods across long distances.

These roads work by controlling how vehicles enter and leave.

US 131, M-6, 68th St interchange
US 131, M-6, 68th St interchange

There are no traffic signals or intersections on the road. You will not find stop signs or driveways here. Instead, drivers use ramps, also called slip roads, to join the highway. These ramps help drivers change their speed safely.

Motorway Sweden, Switzerland and Italy
Motorway Sweden, Switzerland and Italy

To keep people safe, a median strip separates the two sides of traffic. This divider might be a patch of grass or a barrier. It prevents cars from hitting traffic going the other way.

Other paths do not cross the highway at the same level.

Dolphin and Palmetto Expressway Interchange
Dolphin and Palmetto Expressway Interchange

If a railway or another road meets the highway, it uses an overpass or an underpass. This means the path goes over or under the highway. This design stops conflicts between different types of traffic. It also keeps the flow of cars steady and unhindered. This way, there is no need to stop for pedestrians or trains.

These types of roads began to change in the early 1900s.

Italy was the first country to build them for fast motor vehicles. They opened the A8 road in 1924 to connect Milan to Varese. Germany also built important roads during this time. They built the AVUS in Berlin, which was a closed circuit for testing. In 1932, a road between Cologne and Bonn became a dual highway. This was one of the first roads without speed limits.

Many places around the world use these road systems today.

Hämeenlinnanväylä
Hämeenlinnanväylä

In North America, the first parkways opened near New York City in the 1920s. Canada has the Queen Elizabeth Way, which used a cloverleaf interchange. The Highway 401 in Canada is now a very busy highway. Many countries even use international systems to number their routes. These roads link many different towns and countries together. They help our modern world stay connected and moving.

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🖼️ Images & Media (188)
File:US 131, M-6, 68th St interchange.jpg
US 131, M-6, 68th St interchange.jpg
File:Motorway Sweden, Switzerland and Italy.svg
Motorway Sweden, Switzerland and Italy.svg
File:King's Highway 401 - Ontario (4118726412) (filtered).jpg
King's Highway 401 - Ontario (4118726412)...
File:Hämeenlinnanväylä.jpg
Hämeenlinnanväylä.jpg
File:E6-E20 Olskroksmotet in Gothenburg.png
E6-E20 Olskroksmotet in Gothenburg.png
File:Autostrada del Sole - Italy - panoramio.jpg
Autostrada del Sole - Italy - panoramio.jpg
File:Vienna Convention road sign E5a-V1.svg
Vienna Convention road sign E5a-V1.svg
File:Vienna Convention road sign E5a-V2.svg
Vienna Convention road sign E5a-V2.svg
File:Vienna Convention road sign E5b-V1.svg
Vienna Convention road sign E5b-V1.svg
File:Vienna Convention road sign E5b-V2.svg
Vienna Convention road sign E5b-V2.svg
File:Autostrada between Varese and Como.jpg
Autostrada between Varese and Como.jpg
File:Bundesarchiv Bild 146-1979-025-30A, Reichsautobahn mit zwei KdF-Wagen.jpg
Bundesarchiv Bild 146-1979-025-30A,...

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