Speed Limitation Devices

Limiting the vehicle speed of road vehicles by installing limitation devices constitutes an important measure to improve road safety and to reduce greenhouse gas emissions, pollutant emissions and traffic noise. The EU implemented legislation on speed limiting devices for all heavy goods vehicles and buses above 10 tonnes (M3 and N3 vehicles) on 1/1/1995, and for smaller heavy goods vehicles and buses (M2 and N2 vehicles: 3.5-10 tonnes) on 1/1/2006.

The overall study objective was to assist the European Commission with the evaluation of the current Directive 92/6/EEC on speed limitation devices and to explore and assess options for revising this Directive. More specifically, the objectives were:

To carry out an ex post evaluation of the application of the Directive on heavy goods vehicles and buses, in particular the extension to M2 and N2. What are the main impacts?
To assess whether and how the current Directive could be amended to improve its effectiveness and efficiency, in particular by exploring and assessing the following options:
- Decrease limits for heavy goods vehicles
- Speed limitation devices for light commercial vehicles
- Intelligent Speed Assistance/Adaption (ISA) systems for all commercial vehicles
According to the survey carried out in this project, no particular problems were encountered in the implementation of the Speed Limitation Directive with few exceptions related to administrative and technical costs. The impacts of the Directive on actual vehicle speeds were hard to estimate using historical statistical data due to data limitations. Using more theoretical speed distributions with and without speed limitation devices, it was estimated that overall the impact was a reduction of 9% of fatal accidents on motorways with HCVs involved, 4% of serious injuries and 3% of injury accidents. The effects on emissions, estimated by comparing speed profiles, showed that for the EU as a whole the introduction of speed limiters resulted in a reduction of the total CO2, NOx and PM emissions of HCVs of about 1%.

In the ex ante analysis an evaluation was made for four scenarios for HCV and four for LCV. As data is lacking, the LCV scenarios were limited to LGVs (N1 vehicles) and did not include M1-vehicles. The analysis shows that overall the Intelligent Speed Assistance (ISA) scenarios have the highest increase in road safety for both HCVs and LCVs, in particular when the system is not just informative but also gives active feedback (Voluntary ISA). For both HCVs and LCVs the scenario with such an ISA system shows a reduction in the number of accidents in the EU with HCVs/LGVs involved of about 25% for fatal accidents, 18-19% for seriously injury accidents and 11% for all injury accidents. Decreasing the speed limits to 80 and 90 km/h for HGVs and buses, respectively, leads to a decrease in fatal accidents with HCVs involved of about 5%. A similar reduction percentage was found for the scenario with speed limiters for LGVs set at 100 km/h. The emission impacts are rather different from the safety impacts: the speed limitation devices can have a significant impact on emissions, especially on motorways, while the effect of ISA is in most cases close to zero.




European Commission, DG MOVE


CE Delft, TRT, TNO

Our team

Lars Akkermans, Eef Delhaye
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