A STUDY CARRIED OUT ON THE DIR NORD-OUEST NETWORK
The Direction Interdépartementale des Routes Nord-Ouest (DIR Nord-Ouest) is a government department of the Ministère de la Transition Écologique et de la Cohésion des Territoires. It is responsible for the maintenance, operation and engineering of a network of 1,070 kilometres of national roads and non-concession motorways.
CONTEXT AND ISSUES
A three-month study was carried out on a 28-kilometre stretch of this network. Our ANAIS tool detected 4 alert zones within this perimeter, which were analysed jointly by Mobility by Colas and the DIR Nord-Ouest and will give rise to preventive adjustments. The aim of this study was to identify several alert zones of different types linked to repeated abnormal behaviour (braking, off-roading) by users with different types of vehicle (light vehicles, light commercial vehicles, heavy goods vehicles).
ZONE 1
- Detections: recurring high offsets, mainly by LCVs on an exit lane, with a significant correlation between rain/night and offsets.
- Potential problems identified: short exit lane, sharp bend in the bend, signs hidden by vegetation, need to check the retro-reflectivity of markings and signs.
 |
 |
 |
ZONE 2
- Detections: recurrent heavy offsets, mainly by LCVs with one entry lane, with a high correlation at night.
- Potential problems identified: insufficient roadside markings, rainwater drainage to be checked, surface course repairs required, signs hidden by vegetation.
 |
 |
 |
 |
ZONE 3
- Detections: recurring heavy offsets, mainly by HGVs on the current section, with significant correlations between night and rain.
- Potential problems identified: lack of edge markings in some areas, rainwater drainage to be checked.
 |
 |
ZONE 4
- Detections: recurring high offsets, mainly by HGVs with one exit lane, with significant night-time correlations.
- Potential problems identified: rapid doubling and re-routing before the exit, need to reinforce pre-signalling and signalling.
 |
 |
CONCLUSION
This study, carried out using the ANAIS tool, identified several critical areas requiring improvement to enhance road safety on the DIR Nord-Ouest network. The recommendations resulting from these analyses are based on significant correlations between traffic conditions (rain, night) and the incidents observed, providing a solid basis for implementing corrective measures.