title: Automated section speed control on motorways: an evaluation of the effect on driving speed.
abstract: Automated section speed control is a fairly new traffic safety measure that is increasingly applied to enforce speed limits. The advantage of this enforcement system is the registration of the average speed at an entire section, which would lead to high speed limit compliances and subsequently to a reduction in the vehicle speed variability, increased headway, more homogenised traffic flow and increased traffic capacity. However, the number of studies that analysed these effects are limited. The present study evaluates the speed effect of two section speed control systems in Flanders, Belgium. Both sections are located in the opposite direction of a three-lane motorway with a posted speed limit of 120 km/h. Speed data were collected at different points: from 6 km before the entrance of the section to 6 km downstream from the section. The effect was analysed through a before- and after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of speeds at comparison locations. On the enforced sections considerable decreases were found of about 5.84 km/h in the average speed, 74% in the odds of drivers exceeding the speed limit and 86% in the odds of drivers exceeding the speed limit by more than 10%. At the locations up- and downstream from the section also favourable effects were found for the three outcomes. Furthermore a decrease in the speed variability could be observed at all these data points.
authors.affiliation: Transportation Research Institute Hasselt University, Wetenschapspark 5, BE-3590 Diepenbeek, Belgium. Electronic address: ellen.depauw@uhasselt.be.
authors.forename: Ellen
authors.initials: E
authors.lastname: De Pauw
authors.affiliation: Transportation Research Institute Hasselt University, Wetenschapspark 5, BE-3590 Diepenbeek, Belgium. Electronic address: stijn.daniels@uhasselt.be.
authors.forename: Stijn
authors.initials: S
authors.lastname: Daniels
authors.affiliation: Transportation Research Institute Hasselt University, Wetenschapspark 5, BE-3590 Diepenbeek, Belgium. Electronic address: tom.brijs@uhasselt.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Brijs
authors.affiliation: Transportation Research Institute Hasselt University, Wetenschapspark 5, BE-3590 Diepenbeek, Belgium. Electronic address: elke.hermans@uhasselt.be.
authors.forename: Elke
authors.initials: E
authors.lastname: Hermans
authors.affiliation: Transportation Research Institute Hasselt University, Wetenschapspark 5, BE-3590 Diepenbeek, Belgium. Electronic address: geert.wets@uhasselt.be.
authors.forename: Geert
authors.initials: G
authors.lastname: Wets
mesh_terms: D000054:Acceleration; D000063:Accidents, Traffic / Q000517:prevention & control*; D001331:Automation; D001334:Automobile Driving; D001530:Belgium; D004779:Environment Design; D006801:Humans; D065186:Interrupted Time Series Analysis
keywords: Automated section speed control; Before–after study; Enforcement; Motorway; Speed; Traffic safety