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 crash 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