The Traffic planner plans movements in position and time. Robotic Research’s Traffic planner was originally developed to meet the needs of the DARPA Urban Challenge, and has been updated and modified to support a number of large Army robotics programs since. The primary features of the Traffic planner is time based planning on a road network. Moving vehicles and pedestrians are represented as obstacles in position and time, and the vehicle speed is adjusted to avoid collisions while obeying the constraints of the road network. The road network is represented using an RNDF (Road Network Definition File) that encodes important information about the road network the vehicles are driving on. This includes, but is not limited to, the location of important traffic signs, speed restrictions, lane structure, and intersection mechanics.