Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4978531 | Accident Analysis & Prevention | 2017 | 12 Pages |
Abstract
This paper presents an Empirical Bayes before-after evaluation of the road safety effects of a new motorway (freeway) in Ãstfold county, Norway. The before-period was 1996-2002. The after-period was 2009-2015. The road was rebuilt from an undivided two-lane road into a divided four-lane road. The number of killed or seriously injured road users was reduced by 75 percent, controlling for (downward) long-term trends and regression-to-the-mean (statistically significant at the 5 percent level; recorded numbers 71 before, 11 after). There were small changes in the number of injury accidents (185 before, 123 after; net effect â3%) and the number of slightly injured road users (403 before 279 after; net effect +5%). Motorways appear to mainly reduce injury severity, not the number of accidents. The paper discusses challenges in implementing the Empirical Bayes design when less than ideal data are available.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Rune Elvik, Heidi Ulstein, Kristina Wifstad, Ragnhild S. Syrstad, Aase R. Seeberg, Magnus U. Gulbrandsen, Morten Welde,