Speed is generally considered a central issue in road safety, and one of the basic risk factors in traffic (ETSC, 2010; OECD/ECMT, 2006; Wegman & Aarts, 2006). In 2010, the European Transport Safety Council (ETSC), in its PIN Flash publication, included speed among the three main risk factors on the roads, the others being alcohol and non-use of seat belts. Excessive and inappropriate speed was recognised as the number one road safety problem. Speeding was found to be a primary factor in about one third of fatal accidents and an aggravating factor in all accidents (ETSC, 2010). In a large number of OECD/ECMT countries (OECD/ECMT, 2006), speeding is the number one road safety problem. This is also reflected in the current Road Safety Programme 2011-2020 of the European Commission, within which speed related issues are included in four out of the seven strategic objectives of the Programme (i.e. improved safety measures for vehicles, boost smart technology, better enforcement, a new focus on motorcyclists) (European Commission, 2010; Laiou et al., 2015). The relation between speed and road safety rests on two pillars (SWOV, 2012). The first pillar is the relation between speed and the risk of a crash, and the second pillar is the relation between collision speed and the severity of a crash. The exact relation between speed and the risk of a crash depends on many factors; however, in a general sense, if the driven speeds on a road become higher, the crash rate will also increase. The crash rate is also higher for an individual vehicle that drives at higher speed than the other traffic on that road. The reasons for this accident increase rest on both human factors and vehicle dynamics: on one hand, high speeds reduce the available time for drivers to process information, to decide whether or not to react and to execute a reaction; on the other hand, braking distance is increased at high speeds (proportionally to the square of speed), and it is more common to lose control of a vehicle (e.g. in a sharp curve) at higher speeds (SWOV, 2012; European Commission, 2015). Several studies have attempted to quantify the relationship between speed and accident risk (Elvik, 2009; Elvik et al., 2004; Nilsson, 1982; 2004) and have generally suggested that it is a power function; on a particular road with increasing speed, the accident risk increases more (i.e. the rate of increase becomes steeper) as the absolute speed gets higher. The second pillar relating speed and road safety (SWOV, 2012) is the impact of speed in the severity of a crash. The higher the collision speed, the more serious the consequences in terms of injury and material damage. This relates to the quantity of kinetic energy that during the collision is converted into e.g. heat and matter distortion. In addition, the human body is physically very vulnerable in comparison with the enormous forces released in a collision. In addition to collision speed, the mass difference between vehicles and the vulnerability of the vehicles/road users who are involved are also important factors for injury severity; thus, the effect of speed on the severity of accidents involving pedestrians, cyclists and powered two-wheelers is even more pronounced. Within the above context, road authorities post speed limits in order to instruct drivers about the safe speed to travel in average conditions. However, speed limit violations are very common. Typically 40% to 60% of the drivers exceed the limit, and around 10 to 20% exceed the speed limit by more than 10 km/h (OECD/ECMT, 2006).Given the strong relationship between speed and accident risk and severity, a large number of fatalities and injuries could be prevented if all drivers would only obey the posted speed limits. This thematic ESRA report aims at describing the attitudes and opinions on speeding of road users in 17 European countries, and comparing it amongst countries as well as with regards to demographic characteristics. Some of the ESRA questions have already been used in the SARTRE4 survey, allowing for an assessment of the development in the perspective of previous years. Some others are slightly different or new and can be considered as a first benchmark for future comparison and monitoring across Europe. (Author/publisher)
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