Advanced Driver Assistance Systems : description
Advanced Driver Assistance Systems (ADAS) is used to describe active safety systems on a vehicle that can identify safety-critical situations and take action, either automatically or by sending a warning to the driver.
ADAS systems have developed fast, thanks in part to sensing technology; cameras, radar and laser technology referred to as lidar. This technology is also helping the development of automated and driverless vehicles.
A limited amount of ADAS is mandated through European law. Mostly it is not mandated. ADAS are rapidly being developed and fitted by vehicle manufacturers, often to high-end vehicles, and further regulation is being considered by the EC.
Existing systems mandated on new vehicles
Some mandatory requirements under European law for new vehicles are described below.
Autonomous Emergency Braking Systems (AEBS) senses the chance of a collision ahead and automatically brakes to mitigate or avoid it. EU General Safety Regulation 661/2009 requires medium and heavy commercial vehicles to be fitted with it.
Lane Departure Warning Systems (LDW) senses an unintended lane departure and provides a warning to the driver. EU General Safety Regulation 661/2009 requires medium and heavy commercial vehicles to be fitted with it.
Electronic Stability Control (ESC) detects and reduces loss of traction (skidding) through automatic braking of specific wheels and/or engine braking. EU General Safety Regulation 661/2009 requires all vehicles to be fitted with it.
Automatic Braking Systems (ABS) on cars monitors the speed of wheels and applies the brakes independently to individual wheels in order to prevent them from locking.
Controlling speed and emergency braking: opportunities for ISA and AEBS regulation
There is a review of General Safety Regulation 661/2009 underway by the EC, presenting opportunities for more ADAS to become mandatory. Prior to this review, the EC commissioned TRL (the UK's Transport Research Laboratory) to review ADAS, consult with stakeholders, and make recommendations regarding the value of systems on a safety and cost-benefit basis. TRL's 2015 report[i] made a number of recommendations including:
Intelligent Speed Assistance/Adaptation (ISA)
TRL recommended Intelligent Speed Assistance/Adaptation (ISA). ISA identifies if a vehicle is exceeding a speed limit and can: control the vehicle to below a limit (mandatory ISA); or enable the driver to control whether the system can restrict their vehicle speed and/or the speed it is restricted to (voluntary ISA); or warn the driver if they are exceeding a limit (advisory ISA). The speed limit information is either received from a digital road map, which requires reliable information about posted speed limits from GPS, or from transponders in speed limit signs (known as a ‘beacon system’). All three forms of ISA are considered to be life-saving, but mandatory ISA more so than voluntary or advisory ISA.
TRL recommended AEBS on all vehicles inclusive of cars, and Emergency Brake Light Display. This system automatically deploys rapidly blinking brake lamps in case of hard braking, to warn following drivers.
Support for ISA and AEBS from academics and practitioners
In 2014, TRL carried out in-depth investigations for Highways England into most of the fatal crashes on England’s strategic road network (all England’s motorways and most of its A roads), using crash investigation teams. TRL estimated how many deaths in these fatal crashes would have been prevented if certain ADAS systems had been mandated. TRL concluded more than a third (34%) of deaths studied could have been prevented if AEBS had been mandatory on all vehicles, and one in seven (14%) could have been prevented if advisory ISA had been mandatory.[ii]
Other transport academics have also estimated reductions in deaths through fitment of ISA. It has been estimated that nearly one in three fatal crashes could be prevented by Intelligent Speed Assistance.[iii]
After a successful trial on its bus fleet, Transport for London is requiring ISA to be installed in its new buses by 2017.[iv]
Lane keeping and lane change warning systems
In its report for the EC, TRL recommended an automatic system to keep vehicles in their lane. It also recognised the potential safety benefits of systems that warn of hazards when a vehicle is lane changing.
Lane Keeping Systems
Unlike lane departure warning systems (LDW), which warn a driver of imminent lane departure, a lane keeping system (often referred to as Lane Keep Assist (LKA)) corrects the line of travel of a vehicle automatically, steering it back into the correct position. TRL said in its report[i]: "The effectiveness of LKA is considered to be greater than LDW because the system takes action to prevent the departure event, providing of course it is active and the speed of the vehicle means the system is active. Stakeholders consulted by TRL highlighted that the effectiveness of this system could be dependent on lanes being clearly marked.