Speed Observatory

Speed is directly related to the frequency and severity of accidents (Nilsson and Elvik models). This is why it is important to monitor the speeds used to understand the evolution of the number of accidents and their consequences. The speed measurements are made for ONISR by a specialised research company, using a sampling methodology.

The speeds measured by the observatory do not claim to be absolutely representative of traffic on the entire French road network. On the other hand, their evolution over time is considered to be well representative of the general evolution of behaviour, in other words, these observations are relatively representative, provided that the panel of observation points is stable over time. The results of the speed observatory are therefore intrinsically linked to the panel of measurement points that feed it.

Summary of the results for 2018

In general, the average speeds of passenger vehicles (VT) and light commercial vehicles (VU) in 2018 are slightly lower than in 2017; depending on the type of road network, the average speed is stable or even lower, ranging from 1 km/h to 2 km/h. Only speeds on 2x2-lane roads increase by 2 km/h for both VT and VU.
Truck speeds are on an upward trend, often in the order of 1 km/h for 2-axle trucks (PL2) on 2x2-lane roads.
The VTs observed in 2018 on networks limited to 110 km/h, i.e. alternate highways and 2X2-lane roads, exceeded the maximum authorised speed at 28% and 35% respectively. This rate is 23% on motorways limited to 130 km/h and 30% on 2 or 3 lane roads. In urban areas, it remains high, despite a decrease compared to 2017, on entrances and exits to medium-sized urban areas (38%) and crossings of small urban areas (32%), and is not negligible on arteries in urban centres in medium-sized urban areas (19%).
Compared to 2011-2012, the last period covered by the former Observatory system based on a robust panel of points, the average speed in 2018 is generally similar for heavy goods vehicles despite the slight increase in the last year. While for motorways limited to 130 km/h the average speed remains stable, on roads limited to 110 km/h, an increase is clearly identifiable, while for roads limited to 50 km/h it is a downward trend in speed:

  • on networks limited to 110 km/h; on 2X2 lane roads it generally increases for VT, VU and PL (+ 2 km/h), it also increases on alternate highways for PL (+ 1 km/h);
  • on 2 or 3-lane roads, two periods are distinguished, following the application of 80 km/h on 1 July 2018, the observation conditions are logically heterogeneous. The average speed calculated over all the measurements of the two annual campaigns shows a decrease of 2 km/h.
  • it stagnates or even drops slightly on the lanes limited to 50 km/h.
  • the speeds practiced at night are higher than those practiced during the day.


Average speed (2009-2018) and rate of exceedance of the VMA (2018) of passenger vehicles, by type of network :

The full report and previous reports can be downloaded at the top right of the page.

In addition to the speed observatory, you will find the article from the behaviour observatory.