The ShLOW! Vision
Fighting excessive and illegal speed: to reduce accidents and injury outcome of accidents!
As speed increases it becomes harder to avoid crashes because of longer emergency stopping times. The curves relating speed to distance commence with a horizontal straight section which represents the distance covered during the driver's reaction time (assumed to be 1.5 seconds) with the vehicle proceeding straight ahead at the initial travelling speed. Once braking commences, the speed of the vehicle decreases with distance travelled quite gradually at first and then decreasing more and more rapidly.
1. Emergency stopping distances
The relationship between speed and road accidents has been studied extensively and is very clear: the faster the speed, the greater the probability of a crash and the severity of crashes. All reviews for these studies concord on the following:
-Small changes in mean speeds can be expected to result in measurable and significant changes in crash outcomes.
-Severe crashes (serious injuries and deaths) are much more sensitive to speed changes than crashes in general.
While the risk linked to speed varies from road types to road types, a well recognised model (the Power model) states that, on average, a 1% reduction in the mean speed of traffic leads to a 2% reduction in injury accidents, a 3% reduction in severe injury accidents and a 4% in fatal accidents (Aarts and van Schagen 2006, based on Nilsson 1982). It follows from the high risk associated with speed that reductions in driving speeds (even minor ones) will make an important contribution to reducing the numbers of road traffic deaths and injuries. Speed management is therefore a key element in reaching the EU road safety target. One way of communicating the biological tolerance of road users in a crash at different crash speeds is to use survival or tolerance curves. The example below shows how the risk of death increases with speed for three different collision types.
2. Tolerance curves for different collision types (Green = unprotected; blue = side impact; and red = head on).
Speed is also a highly significant factor in how serious the consequences of accidents invovling vulnerable road users can be (pedestrians, cyclists etc). Seven of ten pedestrians who are hit by a car driving at 50 km/h are killed, whereas at a speed of 30 km/h, nine out of ten survive!
Environmental impact:
Integrating road safety to environmental and health concerns should be at the forefront of modern transport policies. Speed management precisely as the policy option most likely to bring about synergies between horizontal concerns including accidents reduction and climate change mitigation. Today road transport is by far the largest transport mode contributing to CO2 emissions. Fuel consumption and carbon dioxide emissions are a function of speed. Managing driving speeds is therefore a very effective carbon abatement policy. Lower or better enforced speed limits are one of the most certain, equitable, cost effective and potentially popular routes to a lower carbon economy. It is therefore surprising that speed management is rarely mentioned in discussions about carbon abatements, and this is probably because limiting speeds is mistakenly seen as a non-innovative or non-politically viable solution.
For more information, see ETSC's publication "Speed Management, towards safe and sustainable road transport": http://www.etsc.be/documents/Managing%20Speed%20Towards%20Safe%20and%20Sustainable%20Road%20Transport.pdf
Current situation: poor compliance!
Respecting the legal speed limits is the traffic rule most often overlooked by road users. Speeding remains a widespread phenomenon. The OECD estimates that at any one moment 50% of drivers exceed legal speed limits! Changing speed behaviour is therefore different from other road safety areas: it requires a majority of drivers to adopt a different way of driving, whereas compliance with BAC limits (Blood Alcohol Content) and seat belt legislation requires only a minority of "offenders" to change. This problem is set within a social context in which speeding is not yet considered as socially unacceptable as drink driving. The extent of the behavioural and social change needed illustrates the urgency.
The "ShLOW!" Vision: Taking action!
ETSC and its associate partners believe that at every level of society action can be taken to tackle this situation. Speed management is an area of road safety work that has been extensively investigated, and many solutions exist. While political commitment is needed, individuals from all sectors of society can still play a role in demonstrating and implementing these solutions. Using our roads network and being exposed to excessive and illegal speeding by other road users is a daily reality for all of us: after all we are all road users! By focusing on the work of students, "ShLOW!" wishes to involve a segment of society that is particularly concerned:
- Road death is the biggest killer among 18-25 year olds
- Novice drivers in particular endulge in excessive speed without appreciating its consequences
- It is the young generations who will inherit our environment and have to face the challenges of climate change
Throughout the project, 50 students (stemming from engineering to environmental sciences as well as other academic fields) will be selected to receive training in speed management and run a small scale activity of their choice to demonstrate through concrete actions how speed reductions can be achieved: "ShLOW!" is about taking action!