Tailgate driving and the safe gap
Have you ever experienced the irritation of being tailgated? Tailgating is the dangerous practice of driving very close to the vehicle ahead. Probably, if you drive regularly, you will have experienced this annoying behaviour on several occasions.It...
Have you ever experienced the irritation of being tailgated? Tailgating is the dangerous practice of driving very close to the vehicle ahead. Probably, if you drive regularly, you will have experienced this annoying behaviour on several occasions.
It seems that on the vehicle-saturated roads of Malta, this is a widespread driving habit. A greater awareness of the need to maintain a safe gap between moving vehicles will go a long way to reducing the high number of front-to-rear collisions that occur on our roads.
According to studies carried out in the UK, there are various reasons why drivers tailgate. Unnecessarily slow drivers are inducers of tailgating because other drivers get annoyed driving behind them.
Ignorance of the need to leave a safe gap between moving vehicles, aggressiveness and impatience also lead to this kind of behaviour. Moreover, some drivers, especially those of heavy vehicles, drive very close to cars ahead of them in an attempt to maintain the gained speed and so economise on fuel.
Leonard Evans, author of Traffic Safety and the Driver, believes that tailgating is acquired as a driving habit. He affirms that the lack of speed difference between the driven vehicle and the one in front often gives the tailgater a false sense of security.
This false notion is exacerbated by the fact that some people drive in this manner for years on end without having any accident.
Tailgating is risky and stressful to both the victim and the perpetrator. The victim will feel anxious and is likely to commit driving mistakes. On the other hand, the tailgater has his field of vision blocked by the vehicle in front, so he will not be able to plan his driving ahead. He will often fail to choose the better lane in time.
Even in countries where tailgate driving is a prosecutable offence, the police often fail to fine drivers who practise this habit. Under Maltese legislation, tailgating is not considered a major infringement of reckless, negligent or dangerous driving.
Therefore traffic police can't intervene against drivers who tailgate unless their actions lead to an accident in which someone is hurt.
Drivers who tailgate habitually either ignore or else fail to understand the concept of a vehicle's stopping distance. When you slam the brakes, the car will not stop dead.
It moves on until its movement energy is dissipated. Therefore, every driver should leave a safe enough gap from the car ahead to allow time to brake in case of emergency.
Vehicle stopping distance follows a simple formula:
Stopping distance = perception and reaction distance + braking distance
Perception and reaction are both human factors. During an emergency situation, a driver takes time to realise that there is a hazard on the road that requires immediate reaction. This is called perception time and it lasts approximately from a quarter to half a second.
The brain must then transmit an impulse to the driver's foot so that it lifts off the accelerator and slams onto the brake pedal. This is reaction time and usually it varies from a quarter to three quarters of a second.
Both human factors are affected by fatigue, alcohol and lack of concentration.
For instance, by using a mobile phone while driving, you will take longer to perceive danger.
Fatigue and alcohol slow down perception and reaction times considerably, increasing the likelihood of drivers not reacting in time to hazards.
The faster you are going, the further your car will move as you take time to react. For instance, during a seemingly short delay of two seconds, a car cruising at 80 km/h will travel 44 metres. It is only following perception and reaction distance that you will actually press the brake pedal and start causing the car to decelerate.
Braking distance is the distance travelled by a vehicle from when the brakes are applied till it comes to a complete halt. All moving bodies have what scientists call kinetic energy.
During a braking manoeuvre the car's kinetic energy must be dissipated to other forms of energy if the car is to stop. This happens when rubber brake pads squeeze against metal discs that turn with the wheels.
The resulting friction will convert the car's movement energy to heat.
The process is similar to rubbing the palms of your hands vigorously together.
Using simple physics, it follows that the braking distance of a car depends on the following: efficiency of the brake (braking force), the weight of the vehicle and the speed at which the vehicle is travelling.
The braking force depends on the car model, its age and also on the state of the brake pads (or rubber shoes in the case of some rear brakes). Not all cars have the same braking distance, so drivers should know the limits of their car brakes.
Research released by the Australian Bureau of Statistics (ABS) following a November 2003 motor vehicle census shows that the braking distance of old cars exceeded those of comparable newer models. For example, the braking distance for a 1984 Toyota Land Cruiser travelling at 60 km/h was 24.4 m while that of a 2004 Land Cruiser travelling at the same speed was 15.8 m.
Brake pads and shoes should be checked regularly during car servicing and be replaced when they have worn away due to wear and tear. Brake pads on modern cars, which do not have asbestos for health and safety reasons, tend to need to be changed more often.
The greater a vehicle's weight, the more kinetic energy it has, so the longer it takes to stop.
Drivers of trucks, buses and other heavy vehicles should bear this in mind when they tailgate because they pose a serious threat to vehicles in front.
The issue of velocity is slightly more complex. The kinetic energy of a car is related to the square of a car's velocity. This implies that if you double your vehicle's speed, the braking distance will not double but it will be four times as much.
Friction between a vehicle's tyres and the road surface also affects braking distance. A low friction coefficient results when road surfaces are very smooth or wet, or when the tyres' tread is worn flat.
In such conditions, tyres have less grip on the road, so sudden braking might lead to skidding, resulting in longer braking distances and possible loss of steering control.
Cars fitted with anti-lock breaking systems (ABS) will be able to steer while braking but will not necessarily be able to brake in shorter distances.
They are less likely to skid, provided the driver applies a continuous push on the brake pedal, with the electronics doing the rest.
According to statistics published by the Malta Transport Authority (ADT), between 2003 and 2005 there was an average of 1,179 driving-related injuries per year.
These statistics do not cover the multitude of minor accidents where only damage to the vehicle results.
Reducing tailgate driving on the Maltese roads and making all drivers aware of the need to leave a safe gap from the vehicle in front would be in everyone's interest.
Not only would our roads be much safer, but we would be less stressed drivers and perhaps, with a pinch of road courtesy, the joy of driving would be rediscovered by many.
Sources may be provided on request.
It seems that on the vehicle-saturated roads of Malta, this is a widespread driving habit. A greater awareness of the need to maintain a safe gap between moving vehicles will go a long way to reducing the high number of front-to-rear collisions that occur on our roads.
According to studies carried out in the UK, there are various reasons why drivers tailgate. Unnecessarily slow drivers are inducers of tailgating because other drivers get annoyed driving behind them.
Ignorance of the need to leave a safe gap between moving vehicles, aggressiveness and impatience also lead to this kind of behaviour. Moreover, some drivers, especially those of heavy vehicles, drive very close to cars ahead of them in an attempt to maintain the gained speed and so economise on fuel.
Leonard Evans, author of Traffic Safety and the Driver, believes that tailgating is acquired as a driving habit. He affirms that the lack of speed difference between the driven vehicle and the one in front often gives the tailgater a false sense of security.
This false notion is exacerbated by the fact that some people drive in this manner for years on end without having any accident.
Tailgating is risky and stressful to both the victim and the perpetrator. The victim will feel anxious and is likely to commit driving mistakes. On the other hand, the tailgater has his field of vision blocked by the vehicle in front, so he will not be able to plan his driving ahead. He will often fail to choose the better lane in time.
Even in countries where tailgate driving is a prosecutable offence, the police often fail to fine drivers who practise this habit. Under Maltese legislation, tailgating is not considered a major infringement of reckless, negligent or dangerous driving.
Therefore traffic police can't intervene against drivers who tailgate unless their actions lead to an accident in which someone is hurt.
Drivers who tailgate habitually either ignore or else fail to understand the concept of a vehicle's stopping distance. When you slam the brakes, the car will not stop dead.
It moves on until its movement energy is dissipated. Therefore, every driver should leave a safe enough gap from the car ahead to allow time to brake in case of emergency.
Vehicle stopping distance follows a simple formula:
Stopping distance = perception and reaction distance + braking distance
Perception and reaction are both human factors. During an emergency situation, a driver takes time to realise that there is a hazard on the road that requires immediate reaction. This is called perception time and it lasts approximately from a quarter to half a second.
The brain must then transmit an impulse to the driver's foot so that it lifts off the accelerator and slams onto the brake pedal. This is reaction time and usually it varies from a quarter to three quarters of a second.
Both human factors are affected by fatigue, alcohol and lack of concentration.
For instance, by using a mobile phone while driving, you will take longer to perceive danger.
Fatigue and alcohol slow down perception and reaction times considerably, increasing the likelihood of drivers not reacting in time to hazards.
The faster you are going, the further your car will move as you take time to react. For instance, during a seemingly short delay of two seconds, a car cruising at 80 km/h will travel 44 metres. It is only following perception and reaction distance that you will actually press the brake pedal and start causing the car to decelerate.
Braking distance is the distance travelled by a vehicle from when the brakes are applied till it comes to a complete halt. All moving bodies have what scientists call kinetic energy.
During a braking manoeuvre the car's kinetic energy must be dissipated to other forms of energy if the car is to stop. This happens when rubber brake pads squeeze against metal discs that turn with the wheels.
The resulting friction will convert the car's movement energy to heat.
The process is similar to rubbing the palms of your hands vigorously together.
Using simple physics, it follows that the braking distance of a car depends on the following: efficiency of the brake (braking force), the weight of the vehicle and the speed at which the vehicle is travelling.
The braking force depends on the car model, its age and also on the state of the brake pads (or rubber shoes in the case of some rear brakes). Not all cars have the same braking distance, so drivers should know the limits of their car brakes.
Research released by the Australian Bureau of Statistics (ABS) following a November 2003 motor vehicle census shows that the braking distance of old cars exceeded those of comparable newer models. For example, the braking distance for a 1984 Toyota Land Cruiser travelling at 60 km/h was 24.4 m while that of a 2004 Land Cruiser travelling at the same speed was 15.8 m.
Brake pads and shoes should be checked regularly during car servicing and be replaced when they have worn away due to wear and tear. Brake pads on modern cars, which do not have asbestos for health and safety reasons, tend to need to be changed more often.
The greater a vehicle's weight, the more kinetic energy it has, so the longer it takes to stop.
Drivers of trucks, buses and other heavy vehicles should bear this in mind when they tailgate because they pose a serious threat to vehicles in front.
The issue of velocity is slightly more complex. The kinetic energy of a car is related to the square of a car's velocity. This implies that if you double your vehicle's speed, the braking distance will not double but it will be four times as much.
Friction between a vehicle's tyres and the road surface also affects braking distance. A low friction coefficient results when road surfaces are very smooth or wet, or when the tyres' tread is worn flat.
In such conditions, tyres have less grip on the road, so sudden braking might lead to skidding, resulting in longer braking distances and possible loss of steering control.
Cars fitted with anti-lock breaking systems (ABS) will be able to steer while braking but will not necessarily be able to brake in shorter distances.
They are less likely to skid, provided the driver applies a continuous push on the brake pedal, with the electronics doing the rest.
According to statistics published by the Malta Transport Authority (ADT), between 2003 and 2005 there was an average of 1,179 driving-related injuries per year.
These statistics do not cover the multitude of minor accidents where only damage to the vehicle results.
Reducing tailgate driving on the Maltese roads and making all drivers aware of the need to leave a safe gap from the vehicle in front would be in everyone's interest.
Not only would our roads be much safer, but we would be less stressed drivers and perhaps, with a pinch of road courtesy, the joy of driving would be rediscovered by many.
Sources may be provided on request.