In road traffic, the term speeding refers to the state of a motorist driving at a rate exceeding the legal speed limit. For example, a driver travelling at 60 kilometres per hour along a section of road with a speed limit of 50, is considered to be speeding. Speeding has been a major contributory factor to crashes that occur on roads in Accra and the country at large.
The physics of a crash
In a crash, it is the amount of kinetic energy that is imparted which causes injuries or death. This kinetic energy increases exponentially with speed. A doubling of speed is not equal to twice as much kinetic energy, but rather a substantial increase much beyond that and it is much more lethal. A 20% increase in speed is roughly a 45% increase in kinetic energy.
In a high-speed crash, a passenger vehicle cannot handle the force of the crash. As crash speeds get very high, airbags and seat belts do not work as well to keep passengers safe.
Speed influences the risk of crashes and crash injuries in three basic ways:
By the time the driver realizes the need to react, they would have travelled closer to the danger.
This causes a majority of drivers who find themselves in this situation to try stepping hard on the brakes.
This increases the general impact of the crash.
If a driver doubles their speed – for instance from 30 mph to 60 mph – the braking distance does not become twice as far. It becomes four times as far. Travelling at 55 mph, it will take about 6 seconds to stop the vehicle. The vehicle will travel approximately 302 feet before coming to a stop. That is longer than the length of a football field.
When a driver is speeding, other drivers have a hard time telling how fast they are going.
A driver should consider road conditions, weather and road design and slow down when those change. For instance, it is easier to lose traction when speeding around a curve and the high centre of gravity makes it easier to roll over. A driver should slow down before curves.
Safety tips from: Accra Metropolitan Assembly and the Bloomberg Initiative for Global Road Safety