Anti-lock systems which effectively prevent wheel lock have been developed for passenger cars, trucks, articulated vehicles and buses. Six anti-lock system configurations involving individual wheel and axle control are discussed. Also discussed are techniques for evaluating the performance anti-systems; included are straight line braking, the use of a split coefficient surface and braking in a turn. The results of computer simulation studies and vehicle tests conducted to evaluate the performance of the various anti-lock system configurations are presented. It is concluded that the best anti-lock system configuration for a particular vehicle requires a trade off among vehicle design characteristics, desired level of braking, and vehicle handling performance and cost.