The role of automatic speed limit enforcement in speed management in Portugal

Abstract

Excessive speeds are a major contributing factor for road accidents. Research has shown that both accident risk and injury severity resulting from accidents vary with speed due to physical reasons and to psycho-physiological effects on road users; relations between these factors have been found at the individual and the system levels.

Most road safety plans include speed management as a tool for mitigating road crash consequences and reaching the targeted safety levels. In that perspective the Portuguese Road Safety Plan is no exception, and an integrated set of safety interventions is programmed and being implemented, including legislation update, road infrastructure improvements, information campaigns, the use of ITS and enforcement activities.

Automatic systems have been successfully used for enforcing compliance with speed limits in several countries, resulting in lower prevalence of excessive speeds and safety improvements in the vicinity of their installation sites. The investments for the implementation of these systems consistently show favourable benefit-cost ratios, provided the installation sites are carefully selected. In fact, automatic speed enforcement was identified as a road safety best practice in SUPREME, a 6th Framework European research project, in which best practices in road safety were collected, analysed and summarised. However, in some countries, social resistance to this type of devices may arise, if misunderstandings are allowed to develop about their main function.

In this paper a presentation is made of the technical criteria being applied in Portugal for the selection of eligible sites for installation of automatic speed enforcement and for monitoring its safety effects. Also, a brief description is made of the related activity being taken within the Portuguese Road Safety Plan to ensure the needed social acceptability of this safety intervention.