In Britain, the old Road Traffic Act restricted speeds to 2 m.p.h. (miles per hour) in towns and 4 m.p.h, in the country. Later parliament increased the speed limit to 14 m.p.h. But by 1903 the development of the car industry had made it necessary to raise the limit to 20 m.p.h. By 1930, however, the law was so widely ignored that speeding restrictions were done away with altogether. For five years motorists were free to drive at whatever speeds they liked. Then in 1935 the Road Traffic Act imposed a 30 m.p.h. speed limit in built-up areas, along with the introduction of driving tests and pedestrian crossings.
Speeding is now the most common motoring offence in Britain. Offences for speeding fall into three classes: exceeding the limit on restricted road, exceeding on any road the limit for the vehicle you are driving, and exceeding the 70 m.p.h, limit on any road. A restricted road is one where the street lamps are 200 yards apart, or more.
The main controversy (争论) surrounding speeding laws is the extent of their safety value. The Ministry of Transport maintains that speed limits reduce accidents. It claims that when the 30 m.p.h, limit was introduced in 1935 there was a fall of 15 percent in fatal accidents. Likewise, when the 40 m.p.h, speed limit was imposed on a number of roads in London in the late fifties, there was a 28 percent reduction in serious accidents. There were also fewer casualties (伤亡) in the year after the 70 m.p.h. motorway limit was imposed in 1966.
In America, however, it is thought that the reduced accident figures are due rather to the increase in traffic density. This is why it has even been suggested that the present speed limits should be done away with completely, or that a guide should be given to inexperienced drivers and the speed limits made advisory, as is done in parts of the USA. What measures were adopted in 1935 in addition to the speeding restrictions