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Road safety

Road safety is a cross-sector theme in the field of transport, affecting all the information, systems and measures which aim to avoid road traffic accidents or reduce their impact. ITS may, directly or indirectly, contribute to road safety. The development of roadside monitoring and warning systems which alert users to driving difficulties is one example. There are also on-board driving assistance systems which compensate for driver errors and help the driver to carry out their driving activity by informing them of a certain number of operations that can improve their vehicle management, or even by carrying these out for them. Other systems are intended to directly protect users (user protection). Finally, in a different way, Automated Control improves road safety by helping to enforce traffic regulations.

For more information: site de la sécurité routière


  • Weather station and water depth sensor (SARI project)

Monitoring and warning systems

Monitoring and warning systems are generally located by the roadside and are intended:

  • for monitoring systems,  to deliver information to road system managers on local conditions  which may affect the state of the road due to poor weather conditions, recurrent or one-off events likely to affect user safety and their journeys;
  • for warning systems,  to provide road users with detailed information resulting from any damage or a temporary incident which may pose a risk in terms of the driving activity. The warning systems generally complete existing road signing.

In monitoring systems, it is important to distinguish those pertaining to the state of the road independently of traffic conditions.  The systems intended to manage poor weather situations come under this category: Road weather stations used to manage winter situations and systems to measure the reduction in visibility in fog.  There are also systems which characterise local reduction in road grip such as the measurement of water depth.

Other monitoring systems concern events related to the traffic and user safety.  Automatic Incident Detection (AID) is an essential application for road managers, in particular on motorways and urban dual carriageways.

Certain access management systems can also contribute to road safety by detecting the unauthorised entry of vehicles onto roads or structures by estimating the real-time risks.

Warning systems are intended to provide users with road safety information either in direct relation to driving behaviour (inappropriate speed etc.) or in relation to an event (incident or accident) or with descriptive information on the deterioration in traffic conditions. The media used to relay these warnings may reinforce existing signalling VMS or the warning system’’s own specific display. These systems may come under one of these categories or combine several approaches according to the means of activation and the media used. The following are examples of these systems (non-comprehensive list):

For driving behaviour:

  • speed detection signs,  which provide a reminder of the speed limit when users drive past over the speed limit;
  • speed warnings which display a warning message when the legal speed limit is exceeded (« educational » speed cameras, average speed and distance between vehicles on the A10 motorway) ;
  • advanced signalling of occasional events such as the closure of level crossings, the protection of coach stops and pedestrian crossings.

There are a wide variety of warning systems which can also be combined. Recent research has looked at this issue, in particular the SARI (nouvelle fenêtre)  projects. The different SARI themes have made it possible to define and experiment warning systems in the following conditions:

  • RADARR project: a system to warn of inappropriate speeds in bends by reinforcing existing signalling (warning lights);
  • IRCAD project: Poor weather warning system for bends using VMS;
  • VIZIR project: Junction warning system using VMS;
  • AJISE project: Legal, Indiviudal, Social and Economic Acceptability of SARI warning systems.

For more information, see the website on the PRAC (nouvelle fenêtre) conference.

When the warning messages are delivered by VMS, the information messages should be produced in compliance with existing recommendations.


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On-board Driving Assistance Systems (DAS)

Driving Assistance Systems (DAS) are a highly dynamic sector. Most of the current systems available as standard in vehicles are intended to compensate for driver errors, however there has been a recent trend towards integrating systems to improve comfort and energy efficiency.

Driving Assistance Systems improve safety by helping the driver to avoid accidents or at-risk situations or by minimising the consequences of these. The main categories of assistance are the following:

  • Emergency calls (or eCall): This is a box capable of detecting an impact thereby making it possible to inform the emergency services more rapidly. Some infrastructure components are equipped with these systems.
  • Assisted Braking Systems: These are Electronic Braking Systems (EBS) or Anti-lock Braking Systems (ABS).
  • ESP (Electronic Stability Program): An electronic device which stabilises the vehicle’s trajectory. There are also systems for monitoring lateral trajectory (Lane Departure Warning - LDW).
  • Visibility in adverse conditions (visibility enhancement): The aim is to improve visibility for the driver with cameras which can “see” in the dark or fog.
  • Speed Regulation Systems(SRS): These include the now near ubiquitous speed and cruise controls, but also the increasingly common Adaptive Cruise Control (ACC). Another recent innovation, not yet on the market is Intelligent Speed Adaptation ISA.

Descriptions of other driving assistance systems for intelligent vehicles can be found on the European Community’s thematic site (nouvelle fenêtre).

 There are numerous assistance options which can also be combined, but it is difficult to assess the effectiveness of the systems obtained. On a more general note, the development of new on-board technologies raises questions concerning:

  • poorly-designed interfaces which may overload the driver with information and generate new risks;
  • the social acceptability of these new systems may hinder their development.

Scientific research is being carried out to study the reliability and the impact of new generations of driving assistance systems by means of road tests (Field Operational Tests FOT).

With the development of mobile communications systems (smartphones, tablets etc.), there are more categories of driving assistance systems with new functions such as driver information (maps, traffic, augmented reality etc.) or environmental assistance (ecodriving). However, the major breakthrough for these systems may well be the development of wireless communications and the accuracy of the information available or measured by sensors on the vehicle.

The Intelligent Co-operative Road

For a long time, manufacturers have settled for fitting their vehicles with autonomous systems, but the current trend is towards an integrated and systemic approach in liaison with the traffic authorities and managers.  Combining mapping data (GPS) with that detected by vehicle sensors (cameras, radars etc.) makes cooperative driving a real possibility. Current research has lead researchers to envisage the implementation of vehicle to vehicle communication systems and vehicle to infrastructure systems which would make it possible to install incident detection systems (congestion, ice, roadworks etc.) and warnings upstream of dangerous situations. Research projects on these themes involving French teams are funded by the European Commmission (CVIS project).

Towards automated driving?

The ever-increasing sophistication of vehicles and the multiplication of driving assistance systems seem to be leading towards automated driving becoming a reality in the medium term. It is almost already a reality, and in 2010 there were several road demonstrations of automated vehicles (Google car (nouvelle fenêtre), SARTRE Project (nouvelle fenêtre), DARPA challenge (nouvelle fenêtre), Vislab challenge (nouvelle fenêtre), etc.). Automated vehicles already exist in France (Cybercars project (nouvelle fenêtre) INRIA) as technical demonstrators, although several more years of research and testing will be required before these are available to the general public.



Traffic regulation enforcement may make use of ITS in the form of Automated Control (AC)


Traffic regulation enforcement

Automated Control (AC) is a priority for the government. The aim is to ensure that users follow the Highway Code is better (including users of light vehicles, heavy goods vehicles, two-wheeled motor vehicles) and in particular with regard to:

  • speed limits (using fixed or mobile speed camera systems)
  • stop signals (red lights, level crossings).

AC has made a significant contribution to improving road safety, notably by reducing the seriousness of accidents (reduction of number of people killed on the roads)

The objective for AC deployment was set at 4,500 systems including 800 red-light cameras by the end of 2012 (more than 400 already installed end of 2010).

AC comes under the umbrella of Intelligent Transport Systems due to its use of various technologies (radars, electromagnetic loops, transmission, encryption etc.) in an inter-ministerial technical chain starting with the detection of the offence through to the final processing of the penalty notice.

The strength of the system is its inviobility and the rapid processing of offences detected on the ground which are then transmitted and recorded at the CACIR (Automated Centre for Recording Road Traffic Offences) before being finally processed at the CNT (National Processing Centre) in Rennes.

To find out more about implementing AC, see the pages below:


User protection

ITS play a role in protecting users by means of

  • on-board systems to protect drivers and their passengers;
  • systems to protect so-called vulnerable users: Pedestrians, cyclists, two-wheeled motor vehicle users.

Of all the on-board protection systems available, the best known are the airbags or inflatable safety cushions intended to protect passengers in the event of a collision by softening the impact with components of the vehicle (the steering wheel, the front seat headrest for the back seat passenger etc.). These are used in association with seatbelts and pretensioners (SRS). Generally speaking, these systems are known as "passive safety" or "secondary safety" and aim to minimise the seriousness of an accident.

Systems situated outside of the vehicle are also being developed to protect so-called vulnerable users. There are also systems available to warn drivers of the presence of a pedestrian or cyclist in the vicinity of the vehicle in order to reduce the risk of collisions. "Intelligent" car bonnets are also being studied, designed to lift automatically in the event of a collision with a pedestrian.

As far as two-wheeled motor vehicles are concerned, notable developments include motorcycle airbags and inflatable safety vests. The DAMOTO (nouvelle fenêtre) project works on designing and developing methods and tools to trigger passive and active safety systems.  Another experimental project SAFERIDER (nouvelle fenêtre) aims to study the interest and transfer of driving assistance vehicles for cars to motorcycles.