Reading passage
The motorway, a wide road designed for fast motor traffic, is a surprisingly recent invention. The first road reserved exclusively for motor vehicles opened in Italy in 1924, running between Milan and Varese. Before their arrival, long-distance drivers had to share narrow roads with cyclists, pedestrians and horse-drawn carts. Germany followed in the 1930s with its autobahn network, which was built partly to reduce unemployment and partly for military purposes. These early roads demonstrated that separating fast traffic from local traffic could dramatically reduce journey times.
The largest motorway programme in history began in the United States. In 1956, President Eisenhower signed the law that created the Interstate Highway System, a network that eventually grew to more than 75,000 kilometres. Eisenhower had been impressed by the German autobahns and by the difficulty of moving military convoys across America on ordinary roads. Building it was the largest public works project the world had ever seen at that time. The system took nearly four decades to complete and transformed the American economy.
Motorways share several design features that make them safer and faster than ordinary roads. They have controlled access, which means vehicles can only join or leave at special junctions. The two directions of travel are separated by a central barrier, and there are no traffic lights, crossroads or pedestrians. Gentle curves and wide lanes allow vehicles to maintain high speeds, while emergency lanes provide a safe place to stop. Bridges and tunnels carry the road across rivers and hills without steep gradients.
Supporters of motorways point to enormous economic benefits. Faster roads reduce the cost of moving goods, allow businesses to serve wider markets, and give workers access to more jobs. One study in the United States estimated that the interstate network returned far more in economic value than it cost to build. Motorways also tend to have lower accident rates per kilometre travelled than ordinary roads.
Germany's autobahns are famous for having sections with no general speed limit, yet their safety record is better than that of ordinary German roads. Engineers credit this to the strict separation of traffic and high construction standards. Even so, debate continues about whether a general limit should be introduced, both to reduce accidents and to cut fuel consumption. Most other countries set motorway limits of between 100 and 130 kilometres per hour.
Critics, however, argue that new motorways often create the very congestion they were meant to cure. When a road is widened or a new one opens, journeys become easier, so more people choose to drive, and within a few years traffic returns to its previous level. Economists call this phenomenon induced demand. In addition, cheap road travel encourages urban sprawl, as families move to distant suburbs and depend entirely on cars.
Motorways also impose heavy environmental costs. Construction destroys farmland and wildlife habitats, while the traffic they carry produces noise and greenhouse gases. In some cities, motorways built in the 1960s cut through poor neighbourhoods, dividing communities and exposing residents to pollution. Several cities, including Seoul and San Francisco, have even demolished urban motorways and replaced them with parks and public transport.
To manage demand, many countries now charge drivers directly. Electronic tolls collect fees without requiring vehicles to stop, and some cities charge motorists who enter the busiest areas at peak times. So-called smart motorways use electronic signs to vary speed limits and open the emergency lane to traffic when congestion builds. These measures aim to squeeze more capacity from existing roads rather than building new ones.
The future of the motorway is uncertain. Electric vehicles will reduce pollution per kilometre, but they will not reduce congestion or the demand for land. Some planners predict that automated vehicles will allow cars to travel closer together, increasing capacity without new construction. Others argue that the age of motorway building is ending, and that investment should shift to railways and public transport instead. Whatever happens, the motorways already built will shape cities and lifestyles for many decades to come.