Development of surrogate measures for crash-based safety estimation

Bhagwant Persaud
Taha Saleem
Yongsheng Chen

The paper investigates the validity of promising surrogate measures by investigating the link between such measures and safety. Such measures, if shown to be valid, can be used in two ways: a) to evaluate a newly implemented measure for which data can be quickly assembled to estimate the effect on the safety surrogate and, by implication, the effect on expected crashes, and b) to estimate the safety effects of a proposed change by first estimating the effect on the safety surrogate and then relating that outcome to the expected change in crashes. The idea is not new. In fact, several researchers have been working on various complementary pieces of the puzzle. The key missing link is in developing measures that can in fact be linked explicitly to safety as manifested in expected numbers of crashes. In addressing this void, two complementary sets of models are explored – models to relate surrogate measures to design features and models to relate crashes to surrogate measures. The first set successfully modeled simulated conflicts for urban signalized intersections estimated from micro-simulation software, complementing the models for measured and predicted speeds for roundabouts that have been developed in our recently published research. Models relating these surrogate measures to observed crashes suggest that there is promise in the approach of using certain surrogate measures for crash-based safety estimation.



Cost Benefit Analysis (CBA) workshop in Stockholm

An open seminar and workshop in Stockholm will be held on 25-26 April 2018. The workshop deals with the use of CBA as a basis for decision-making in the public sector. The workshop is organized by, among others, Professor Jan-Eric Nilsson, VTI.

The 6st Humanist Conference

The 6th HUMANIST Conference will take place 13-14 June 2018 in the Hague, The Netherlands. The scope of the conference covers a wide range of topics on Human Factors in Transport. Tania Willstrand and Alexander Eriksson will present their research results.



VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...


Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...


Swedish road safety spreads internationally

Sweden is a leading country in terms of road safety, and the research conducted by the Swedish National Road and Transport Research Institute (VTI) has contributed to increased safety. VTI’s remit includes disseminating research results and keeping up to date...


A greater understanding of cyclists' behaviour

Cyclists are often accused of not following traffic rules and being hooligans on the road. New research shows that there is no support for this perception. "Our observations reveal no such general anarchy" says Sonja Forward, researcher at VTI.


New technology for road surface measurement tested

VTI has tested a new scanning-laser technology for road surface measurement. The tests show the new technology for comprehensive transverse-profile measurement provides dependable values in measuring transverse profile and rut depth.


Ulf Sandberg has been presented with the TTI Lifetime Achievement Award 2018

VTI’s Senior Research Leader Ulf Sandberg has been presented with the TTI Lifetime Achievement Award 2018 for his work on research into tyres and road surface.