The ICT radar is an information-communication technology system for early warning and collision avoidance on roads and motorways. This radar uses special sensor network, which - spanned over the moving vehicles and road obstacles - transmits automatically warning signals to the back of column and enables distant drivers to stop in time or to do such operations automatically. Large-scale simulations have been carried out, which show that in typical scenario the number of collisions decreases from some great number to zero as the radar usage increases from 0% to 100%. Even at 50% of random radar usage almost all huge collisions are excluded. Typical data of simulations are as follows: one lane road; 50 vehicles randomly spaced, distances drawn from normal distribution, next smoothed; average speed 90 km/h; reaction time of a driver - drawn from random distribution (mean 1 s); first vehicle in column suddenly stopped; model of collisions - domino-alike; protocol of radio communication - modified ALOHA; size of alert packet - 100 bytes containing data: speed, acceleration, coordinates (GPS); kind of alerts: sharp brake, airbag explosion standing vehicle; transmission speed 8 Mb/s; average rate - 1 packet/ms/node; time for reliable warning 0.1 s; range of warning 800 m; coverage area - triangular, backwards oriented; total number of scenarios - 5.000.