Dynamic speed adaptation based on information technology - a theoretical background
Author
Summary, in English
Knowledge on the factors influencing driver speed-behaviour, the relationship between speed and traffic safety and means to influence speed behaviour is systematised. Expert judgements and the high proportion of injury accidents show that improved speed adaptation has the largest safety potential in the following situations: - Road surface-, visibility and weather affected situations (e.g. slippery road, fog, darkness). - Places where sudden speed reduction is needed (e.g. motorway exits, sharp bends). - Encounters with crossing-course both between motor vehicles and between motor vehicles and pedestrians/bicyclists (e.g. at intersections, at zebra crossings).
A study on driver speed behaviour in encounters with pedestrians at a zebra crossing shows that in such situations there is a need for better speed adaptation. In an encounter with a pedestrian, the driver has to be influenced before he reaches the "decision zone" at 50 to 40 m before the zebra crossing, in order to prevent the "signalling by speed" behaviour.
A nationwide survey among 1000 holders of Swedish driving licences shows that the majority of the respondents are positive to a device which automatically lowers the maximum possible speed of the car in slippery conditions and poor visibility, as well as to a device which warns the driver or reduces the speed automatically if the car is about to collide with another road-user. A general system which prevents exceeding the prevailing speed limit is accepted by one third.
A system, which limits the maximal speed of the vehicle in the actual situation via an in-vehicle equipment is proposed. A system algorithm to calculate the appropriate highest speed in different conditions is presented.
The estimated safety effect of the proposed system, if all cars are equipped, is a 20% - 40% reduction of injury accidents reported to the police.
A study on driver speed behaviour in encounters with pedestrians at a zebra crossing shows that in such situations there is a need for better speed adaptation. In an encounter with a pedestrian, the driver has to be influenced before he reaches the "decision zone" at 50 to 40 m before the zebra crossing, in order to prevent the "signalling by speed" behaviour.
A nationwide survey among 1000 holders of Swedish driving licences shows that the majority of the respondents are positive to a device which automatically lowers the maximum possible speed of the car in slippery conditions and poor visibility, as well as to a device which warns the driver or reduces the speed automatically if the car is about to collide with another road-user. A general system which prevents exceeding the prevailing speed limit is accepted by one third.
A system, which limits the maximal speed of the vehicle in the actual situation via an in-vehicle equipment is proposed. A system algorithm to calculate the appropriate highest speed in different conditions is presented.
The estimated safety effect of the proposed system, if all cars are equipped, is a 20% - 40% reduction of injury accidents reported to the police.
Department/s
Publishing year
1997
Language
English
Publication/Series
Bulletin / University of Lund, Lund Institute of Technology, Department of Traffic Planning and Engineering
Volume
142
Document type
Dissertation
Publisher
Lund University Faculty of Engineering, Technology and Society, Transport and Roads, Lund, Sweden
Topic
- Infrastructure Engineering
Keywords
- Teknik
- Technological sciences
- driver acceptance
- appropriate speeds
- speed behaviour
- critical conditions
- Social sciences
- Samhällsvetenskaper
Status
Published
Supervisor
- Christer Hyden
ISBN/ISSN/Other
- ISSN: 0346-6256
- LUTVDG/(TVTT-1014) 1-220/1996
Defence date
14 February 1997
Defence time
10:15
Defence place
Aud.V:C John Ericssons väg 1, Lund
Opponent
- Bernhard Biehl (Dr)