Obstacle and collision warning

Description
System detects obstacles and gives warnings when collision is imminent. Current solutions with limited performance are a separate feature of Adaptive Cruise Control systems which use information obtained from radar sensors to give visual and acoustic warnings. Future systems will use long range/near range radar sensors or LIDAR and video image processing.

Impacts
No reliable safety estimates yet exist. The system should affect especially rear-end collisions and their severity. Behavioural studies in simulators indicate that the system quicken driver reactions in rear-end situations while also some negative effects for e.g. non-equipped drivers have been indicated.

Studies

Automatic collision avoidance system, as an integrated system of forward collision warning and automatic cruise control functions, has the potential to prevent about 6 to 15 percent of all rear-end crashes depending on the source of crash data used for safety benefits estimation. This system effectiveness ranges between 3 and 26 percent according to 95 percent confidence bounds.	The results are based on data collected from a field operational test involving 10 vehicles and 66 drivers and on a system characterization test.	Najm W., Stearns M., Howarth H. Koopmann J. and Hitz J.	2006	Evaluation of an Automotive Rear-End Collision Avoidance System, Volpe National Transportation Systems Center, USA .
The possibilities of current ACC systems in improving traffic safety and reducing congestion seem limited: although positive effects on driver safety and traffic safety were found, some negative effects are a cause for concern. The ACC systems should be extended with a Stop-and-Go functionality and preferably also with collision warning or collision avoidance capabilities.	The results presented were based on a literature study on subject.	Hoethink, A.	2003	Advanced Cruise Control in the Netherlands: a critical review. 10th World Congress and Exhibition on Intelligent Transport Systems and Services, Madrid 16-20 November 2003. Proceedings, CD-ROM. ERTICO, ITS Europe
Effectiveness of Forward Obstacles Collision Warning Systems using the in-vehicle information and the road-side information was evaluated introducing the velocity at 100m point forward the obstacle as a new evaluation criteria. As the results, it was clarified that the integrated road side/in-vehicle information has significant effectiveness.	Simulator studies	Yamada, K.	2002	Evaluation of forward obstacles collision avoidance support system using driving simulator. 9th World congress on intelligent transport systems, Chicago October 14-17 2002. Proceedings, CD-ROM.
The number of annoying warning can be reduced. It is also possible to predict the braking action, using the Hidden Markov Models applied in real traffic situations.	A collision warning system based on the prediction of driver's braking action was developed. Results of the study are based on field experiments with 18 people.	Sakabe M., Watanabe K. & Ohno H.	2002	Development of a collision warning system based on the prediction of driver's braking action. 9th World congress on intelligent transport systems, Chicago October 14-17 2002
Without warning, the braking time increases as the awareness level decreases. A warning system that can compensate for a decline in driver perceptual ability caused by sleepiness is effective.	Results of the study are based on measurements of reaction time and some measurements in real traffic situations.	Yamada, K.	2000	Driver reaction time to forward vehicle collision warning - effectiveness of warning system under low awareness level. 7th World Congress on Intelligent Transport Systems, Turin 6-9 November 2000. Proceedings, CD-ROM. ERTICO - ITS Europe