Hastighetsspridning och trafiksäkerhet

Download

This study describes the state of knowledge in terms of speed distribution and traffic safety. Real changes in speed-distribution and estimated accident risk for three different traffic safety measures are studied. The aim is to gain a better understanding of the relation between speed distribution and traffic safety. The study consists of: a literature review on models for the relationship between speed and accident risk, a study on the relation between measures from the speed distribution of different traffic safety measures and a study comparing different models that estimate accident risk. The literature review shows that several studies during the 1960s and 1970s that analysed individual risks in relation to the choice of speed showed a U-shaped relationship between speed and accident risk. More recent studies suggest that the relationship is rather monotonically increasing where the slope becomes steeper for higher speeds. This means that there is an increased risk of being involved in an accident for higher speeds. However, there is no overall increased risk if you drive slower than the average speed on the road. In the second study it is shown that measures like new speed limits move the entire speed distribution towards lower speeds, but for measures like speed cameras and ISA, the speed distribution is changes most for higher speeds. In the third study, where different models that study accident risk and speed levels are compared, it is shown that models developed to estimate an individual driver's risk give an unreasonable impact on risk change compared to aggregate models such as the power model. An alternative approach to take into account a change in the speed distribution is to use the power model at an individual level. The greatest difference is obtained for higher severity injuries and measures such as speed cameras and ISA where the speed distribution changes its shape the most.

MEET US


19-20
Oct

ERPUG 2017

The five year anniversary of  European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017. 

LATEST NEWS


2017-07-05

Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...


2017-06-29

Tomas Svensson new director-general

Tomas Svensson was today appointed Director-General of VTI. Tomas has been acting Director-General since January 2017. 


2017-05-30

Crash testing bicycles at VTI

For the first time single bicycle crashes have been simulated at the VTI crash safety laboratory.


2017-05-15

A case study exploring firefighters’ and municipal officials’ preparedness for electrical vehicles

A VTI-study presents a social perspective on new vehicle technology. It explores the self-reported preparedness of the fire departments (i.e., rescue services) in Sweden’s three largest cities regarding rescue operations involving electrical vehicles (EVs).


2017-05-02

Pioneering research on and about bicycles at VTI

Under what circumstances might cyclists lose tyre grip? What actions could then be taken to prevent a crash? VTI is currently developing a theoretical model of the behaviour of bicycle tyres during braking and steering in different situations and on different...


2017-05-02

Virtual pedestrians create efficient stations

If more people are to choose sustainable travel, then the public transport stations of the future must be designed so that pedestrians can get where they are going quickly, without congestion or queues. The Swedish Road and Transport Research Institute (VTI)...