Safe Speeds and Credible Speed Limits (SaCredSpeed): New Vision for Decision Making on Speed Management

Speed is an inherent characteristic of mobility and a hazard to safety. Several approaches exist of how to manage speed. In the Netherlands, the emphasis has mainly been on harm minimisation during the last decades, due to the implementation of the Sustainable Safety vision. Speed management remains a core business in this vision, by means of an integral approach of speed management measurements. A request from a number of regional authorities to assist them in developing a decision support system for speed management was the starting point for elaborating SWOV's vision on safe speed and credible speed limits (SaCredSpeed) into an algorithm. This vision and algorithm are presented in this paper. The SaCredSpeed algorithm uses input data of design, image and traffic characteristics of a particular stretch of road to asses a safe speed and speed limit for that particular situation. This safe speed is related to the real speed (V90; optional), and, depending on the fit, the credibility of the speed limit, the enforcement situation (optional), the network function of the road, the condition of the adjacent roads, and the priorities the decision maker wants to set, SaCredSpeed offers suggestions for adaptations. These can consist of a) speed limit adaptations, b) road design adaptations or c) additional enforcement adaptations. This integral approach to speed management from the view of safety and credibility can be a good addition to other speed or safety instruments that exist. The paper concludes with suggestions for further research and international cooperation.

[1]  Michael Kyte,et al.  Effect of Environmental Factors on Driver Speed: A Case Study , 1998 .

[2]  S. J. Ashton,et al.  Some characteristics of the population who suffer trauma as pedestrians when hit by cars and some resulting implications , 1979 .

[3]  Rune Elvik,et al.  Cost-Benefit Analysis of Police Enforcement , 2001 .

[4]  D. Zaal TRAFFIC LAW ENFORCEMENT: A REVIEW OF THE LITERATURE. , 1994 .

[5]  Nicole van Nes,et al.  Opportunities to Improve Speed Behavior: Credibility of Speed Limits and the Use of ISA , 2010 .

[6]  M Jessurun,et al.  Effect of road layout and road environment on driving performance, drivers' physiology and road appreciation. , 1995, Ergonomics.

[7]  M P Hagenzieker 'MOPED ON THE CARRIAGEWAY': FROM TRIAL TO MEASURE. AN OVERVIEW OF THE STATE OF AFFAIRS , 1994 .

[8]  Stefan Siegrist,et al.  Police Enforcement Strategies to Reduce Traffic Casualties in Europe , 1999 .

[9]  Mark A. Elliott,et al.  Road design measures to reduce drivers' speed via 'psychological' processes : a literature review , 2003 .

[10]  Ingrid van Schagen,et al.  Driving speed and the risk of road crashes: a review. , 2006, Accident; analysis and prevention.

[11]  Fred Wegman,et al.  Safe and credible speed limits: a strategic exploration , 2004 .

[12]  Rune Elvik,et al.  The Handbook of Road Safety Measures , 2009 .

[13]  J. Archer,et al.  THE IMPACT OF LOWERED SPEED LIMITS IN URBAN AND METROPOLITAN AREAS , 2008 .

[14]  F Wegman,et al.  Advancing sustainable safety in the Netherlands , 2007 .

[15]  Andrew C. Lemer Research Results Digest 318-An Expert System for Recommending Speed Limits in Speed Zones , 2004 .

[16]  N. Haworth,et al.  VISION ZERO: AN ETHICAL APPROACH TO SAFETY AND MOBILITY , 1999 .

[17]  Jim Langford,et al.  Balance between harm reduction and mobility in setting speed limits: A feasibility study , 2005 .

[18]  Charles Goldenbeld,et al.  The credibility of speed limits on 80 km/h rural roads: The effects of road and person(ality) characteristics. , 2007, Accident; analysis and prevention.