J. ARCHER1 and K. VOGEL2
CTR, Kungliga Tekniska Högskolan, Stockholm, Sweden; 2 VTI, Linköping, Sweden E-mail: email@example.com; firstname.lastname@example.org
As the number of people who reside and work in urban areas increases, so, too, do the needs and demands placed on the infrastructure. This has led to severe congestion in many European cities, a situation which affects not only the environment in terms of pollution, but most notably levels of traffic safety. In Europe, tens of thousands of people are killed in road traffic accidents, and more than 1 million are injured each year at a cost, which is estimated to exceed the total European Union budget by a factor of two. The majority of accidents involving injury occur within urban areas often at junctions, while the number of fatalities outside these areas is greater, largely as a result of higher speed. Traffic safety research has shown a biased interest in the problems associated with motorway and rural areas in the past. There are many reasons, which advocate a greater interest in urban areas, in particular, those related to the safety of unprotected road users. In urban areas the traffic system context is more complex, where a mixed road user environment prevails and greater perceptual and cognitive demands are placed on road users. In the past, many of the more successful safety countermeasures have focused on designing the roadway to meet the needs and limitations of road users. These solutions have, however, proved to be very costly. Today, new and relatively cheap technological solutions referred to as Intelligent Transport Systems (ITS) have been developed which have the capacity to reduce exposure, accident risk, and accident severity. While the long term effects of these systems are largely unknown, and problems associated with standardisation and legislation are in need of resolve, systems such as Intelligent Speed Adaptation and advanced traffic control systems have shown great potential with regard to the traffic safety problem in urban areas. In order to effectuate this potential, a great deal of integrated multi-disciplinary research is required.
1. INTRODUCTION The last century of the second millennium has seen vast improvements in the living conditions and economic wealth of the industrialised nations of the world, and consequently a large growth in population, particularly in urban areas. The growth of cities and towns has also led to an increase in the need for mobility, and a consequent increase in the numbers and types of vehicles occupying the road infrastructure. The exponential increase in the number of vehicles during the twentieth century has far outweighed the projected capacities and adaptive capabilities of the existing road infrastructure systems, this has resulted in a situation of congestion and frustration among road users of all types and has had significant detrimental effects for traffic safety in terms of the unacceptable numbers of road accidents involving fatality and injury. During 1997, there were approximately 45 000 fatalities, and 1.3 million injuries reported from road traffic accidents within the European OECD countries according to statistics taken from the International Road Traffic and Accident Database (IRTAD). The costs of such accidents within the European Union are estimated to be in the region of 160 billion ECU per year, thereby exceding the total annual budget for the EU in 1997 (89 billion ECU). Statistics indicate that while approximately two-thirds of all fatalities occur outside urban areas, two-thirds of the total number of injuries occur inside urban areas. The outcomes of urban accidents are usually less severe in terms of the numbers of injuries and fatalities as a direct result of the greater limitations imposed on speed. Mainly for this reason, most of the international and national traffic safety research has focused on motorways and major roads...