Many ISA systems provide information about driving hazards, e.g. high pedestrian movement areas, railway crossings, schools, hospitals, etc., and limits enforced by speed and CCTV cameras at traffic lights.
ISA was born in France when Saad and Malaterre (1982) carried out their study of driver behaviour with an in-car speed limiter.
There followed a series of projects in Sweden, culminating in the large-scale trial of 1999 to 2001, when there were close to 5000 ISA-equipped vehicles on Swedish roads (Biding and Lind, 2002).
Most of these vehicles were equipped with an informative or warning version of ISA, but a few hundred used an intervening system, being fitted with a haptic throttle, whereby the accelerator pedal became stiffer when the speed limit was exceeded.
A kick-down function was provided to allow drivers to overcome this resistance.Literature Review and Scoping Study January 2006 Project Partners: The University of Leeds and MIRA Ltd After ISA regulation entered into force in the EU on 8 July 2022, a speed limiter ISA law entered into force in the UK on 6 July.
The use of radio beacons is common when ISA systems are used, to control vehicle speeds in off-road situations, such as factory sites, logistics and storage centres, where occupational health and safety requirements mean that very low vehicle speeds are required in the vicinity of workers, and in situations of limited or obscured visibility.
Optical recognition technology has focused on recognizing speed signs,[6] road markings[9] and roadside objects such as "cat's eyes".
By measuring the rotation of the road wheels over time, a fairly precise estimation of the vehicle's speed and distance travelled can be made.
Then, by combining speed and distance data with factors such as the angle of the steering wheel and feedback from specialized sensors, e.g., accelerometers, flux gate compass, gyroscope, it can plot the path taken by the vehicle.
Dead reckoning is prone to cumulative measurement errors, such as variations between the assumed circumference of the tyres compared to the actual dimension, which is used to calculate vehicle speed and distance travelled.
Other measurement errors are accumulated when the vehicle navigates gradual curves that inertial sensors, gyroscopes and/or accelerometers, are not sensitive enough to detect, or due to electromagnetic influences on magnetic flux compasses, from passing under power lines or when travelling across a steel bridge, and through underpasses and road tunnels.
Some car manufacturers have expressed concern that some types of speed limiters take control away from the driver.
Conversely, the experience of some drivers with driving under an active ISA system has been that they find they can pay more attention to the roadway and road environment, as they no longer need to monitor the speedometer and adjust their speeds on a continuing basis.
[citation needed] Some studies which pre-date the development of ISA systems indicated that drivers make relatively little use of the speedometer and instead use auditory cues (such as engine and road noise) to successfully regulate their speed.
[14] This research resulted in a recommendation for wider adoption and promotion of ISA in the Australian National Road Safety Strategy 2011–2020.
(e) its performance targets shall be set in order to avoid or minimise the error rate under real driving conditions.In 2012, five out of the 35 governments associated with the ETSC agreed to introduce ISA in all commercial vehicles.
[24] By 2013, adoption of the technology was being considered by the European Commission but was being strongly opposed by UK Transport Secretary Patrick McLoughlin.
[29] In September 2020, the European Transport Safety Council made three criticisms of European draft regulations for ISA:[30] In July 2022, the ESTC restated those reservations, and broadly welcomed ISA, describing it as "a giant leap forward... one of the life-saving systems with the most potential".