Olycksrisk vid lokala ojämnheter och andra ytdefekter


This study has examined, in particular, the effect road surface “local unevenness” has on traffic accident risk. Effects from other road surface defects were also considered but to a lesser extent. Test results are non-significant when considering if local unevenness has any main effect. Local unevenness has also not been chosen as part of any significant term of higher order. The analysis provides no support that local unevenness influences the risk of accidents. With regards to other variables related to the road or road surface, there is a negative correlation between rut depth and accident risk, and a positive correlation between longitudinal gradient and accident risk. Accident risk varies in correlation with IRI (International roughness index) and the permitted speed limit in a way that implies that risk decreases with higher speed and low IRI, and higher IRI and low speed. The risk increases when both IRI and speed increase. Precipitation information is an example of a variable that has been included in the analysis but is not related to the road or road surface. Data indicates that accident risk is lower in places where heavy rainfall often occurs.



Shipping and the environment – research meets reality

Centre for Transport Studies (CTS) in co-operation with Ports of Stockholm invite you to the seminar Shipping and the environment – research meets reality.




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.


Self-driving buses in Sweden next year?

A self-driving, fossil-free bus. This idea might become reality through a forthcoming collaborative project involving the Swedish National Road and Transport Research Institute (VTI), Linköping University and several other participants. The project group aim...


New climate-proof solutions for hard surfaces in cities

High-density road infrastructure that emphasise maximum durability and minimum maintenance create inflexible systems, which put increased stress on urban trees and lead to increased risk for flooding. Over the past five years, the ‘Climate-proof solutions for...


VTI is preparing for automated vehicles

Automation of traffic systems will lead to major changes. The European Union’s (EU) CoEXist research project began in June 2017 with the aim of preparing cities and road operators for the introduction of self-driving vehicles. The Swedish National Road and...


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...


Tomas Svensson new director-general

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