Simulating no-passing zone violations on a vertical curve of a two-lane rural road

A unique simulation was developed to evaluate the performance of a system designed to detect and warn of no-passing zone violations on vertical curves of two-lane rural roads. After the system architecture and the system design were developed, a special software program was written to test the system functions and assess the system performance. Many roadway-, vehicle-, and driver-related parameters were introduced in this simulation to reflect real-world situations as closely as possible. More than 19,500 violation runs were made for the basic scenario to reflect and calibrate the actual conditions of the parameters involved. The simulation was used as a tool to conduct a system evaluation by applying it for cases both with and without the warning system. The simulation outcome for the case without the warning system was very close to the actual real-world condition (1.41 versus 0.71 crashes per year). The simulation runs of the case with the warning system showed that the system could virtually eliminate all head-on collisions, should the violators obey the early warning messages displayed.