If we asked 100 people this question, we would probably get 100 different answers as there are many variables to consider and ultimately how do we define…Going Fast?
The relationship between speed or rather higher speeds and injury severity have long been known…the higher the speed, the greater the possibility and probability for injury; be them minor, severe, life altering or fatal. A true absolute cannot be guaranteed because there are other factors to consider such as type of vehicle involved and what level of protection is given.
Crash resistance in vehicles has improved greatly over years of development, or rather the way in which the impact energy is transferred through the vehicle and minimises the effects on the human body.
Many accidents involving ‘new cars’ may give the impression that there has been an extreme impact force, however, because of the way the car has been designed most of the impact force has been absorbed by the deformed structure of the vehicle (within the crumple zones). However, this transference is limited and the human body is still subjected to extreme forces, especially when impact is made with a much larger vehicle (e.g. car vs lorry) or a solid & immovable object such as a wall or building. Motorcyclists and of course cyclists & pedestrians are subjected to much greater impact forces when the collision speed is higher because of relatively little protection that is afforded to the body.
The relationship between higher speeds and a higher accident rate is also considered to be sound, and indeed many studies and reports from various countries and research organisations have concluded this in their findings. Indeed the World Health Organisation concludes that approximately 30% of road deaths are as a direct result of speed in developed countries and speed accounts for approximately 50% of all road accidents in developing countries.
However, there is a distinction to be made between what is considered as excessive speed, or rather speed which contravenes a speed limit imposed by the authorities, and speed that is considered inappropriate for the road type, road conditions and weather.
Speed limits are imposed by local authorities for various reasons and these are not necessarily concerned with absolute road safety or rather the absolute probability of higher accident rates. Many speed limits are imposed as part of traffic calming measures for a local road network system, or as a result of pressure from local residents or witnessed driving speeds which are perceived as being too fast for the specific road. Speed limits are also imposed because at certain times of day, e.g. during rush hour when the traffic density is high, a higher speed limit would be considered inappropriate. Of course a speed limit may have been imposed because there has been a high incidence of accidents over a recent period. The speed limit is set as a maximum limit for all situations, hence it is a blanket policy to cover all eventualities, however this does not mean that a driver or rider should always drive or ride at the speed limit.
This is where appropriate speed comes to the fore. The driver or rider should always be conscious of the road conditions and the state of the weather as well as traffic density to determine whether a reduced speed is appropriate to reduce the probability of having an accident.
Certainly there are certain types of roads that will allow appropriate speeds up to the speed limit in almost all conditions, these roads are usually motorway or multi carriage highways. There are also roads such as country lanes, that although may have a higher speed limit assigned to it, it may not allow appropriate speeds up to the limit.
IF we consider speed, as it relates to an accident probability then, ultimately any speed that does not allow the rider or driver to react in time to avoid an accident, is considered travelling at excessive speed. E.g. a vehicle that is travelling at 10mph below the speed limit on a country lane and the driver loses control of that vehicle and is involved in an accident would be considered to be travelling at excessive speed either for the road or road conditions and driver’s or rider’s skill limit. However what is really the case is the driver’s or rider’s time to react to a set of changing variables that suddenly present themselves in the road ahead. This reaction time can be affected by many other factors that are not speed related, such as alcohol, drugs or fatigue etc.
If we consider the opposite view; if a vehicle is travelling on a multi carriage highway when traffic density is very low and the speed is e.g. 20mph over the speed limit, would this be considered excessive speed?Well yes, in terms of the imposed speed limit, but not necessarily so, with regards to a high probability of having an accident. The driver will have a much improved view to assess the road and any potential hazards ahead and thus be able to react in time to avoid the hazard.
When the emergency services respond to a road traffic incident, one of the key questions asked is what was the speed of the vehicle involved and ultimately can the impact speed be determined. The various agencies use this information in different ways;
The Ambulance Service use this to gauge the level of potential injuries that may have been sustained and this speed assessment and ‘mechanism of injury’ is then relayed to the trauma teams at the receiving hospital who assess this factor further.
The Police Service use this to gauge how and why the accident or incident occurred and ultimately to apportion culpability or not.
The Fire & Rescue Service use this to gauge the extent of damage caused to the vehicle and potential further hazards from ruptured fuel tanks and risk of fire etc, but also to assess how stable the vehicle is and what level of rescue equipment will be needed to rescue the occupants.
Higher speeds do reduce the driver’s and rider’s ability to process information at a constant rate, hence reaction times are slower with regards of distance travelled. All road users should be aware of any factors that affect reaction times and the ability to process information.
High speed does not mean that there is a greater risk of being involved in an accident in all situations, however depending on the type of road and road conditions and weather and the proficiency of the driver or rider, there is a higher probability of not being able to avoid a hazard that presents itself in the road ahead.
Speed limits are a catch all policy to allow for many environmental conditions and variations in riding and driving experience and proficiency. The use of appropriate speeds and adopting defensive and conservative styles will enable the driver and rider to dramatically reduce the probability of accident incidence.
When responding to road accidents, a common comment from emergency crews is; “They ran out of road, brakes and ideas!” This is usually attributed to single vehicle accidents and usually when the injuries have not been severe, however it illustrates an assessment has been made of a situation that really could have been avoided.
This type of incident affects all vehicles, and a significant percentage of motorcycles are involved in these kinds of incidents, where excessive speed and a misjudgment of a road or conditions has been the major cause of the accident.
All road users should use appropriate speed, and motorcyclists should even more so. Motorcycles have a greater power to weight ratio in most cases and especially in high performance motorcycles, high speed and excessive speed can be gained relatively easily. It is the actual ability to control the motorcycle at those speeds versus a perceived ability to control at those speeds that usually leads to an accident.
As riders, there is a very real temptation to ride at high speed and sometimes those speeds are excessive for all roads and all conditions. Each rider should assess not only the speed they are travelling at but most importantly will they be able to react in time to avoid a hazard that presents itself. A road rider should not be influenced by media images of high speed or by track performances of motorcycle sports riders, as that is not the ‘real’ situation a road rider will face.
Give yourself TIME & SPACE! Ride at Appropriate Speeds!