A method and apparatus for generating a geometric layout of a traffic intersection is disclosed. The method involves receiving intersection capacity data, where receiving includes receiving an identification of a number of intersection legs associated with the traffic intersection, receiving a lane designation designating a plurality of lanes for accommodating permitted vehicle movements between the intersection legs, each lane having at least one associated permitted vehicle movement, and receiving lane width dimensions for accommodating an expected vehicular traffic volume associated with permitted vehicle movements on each of the plurality of lanes. The method also involves generating a geometric layout of the traffic intersection by receiving orientation data defining respective orientations of each of the intersection legs. The method further involves receiving intersection design criteria for designing the traffic intersection, for each intersection leg, combining the lane width dimensions and the intersection design criteria to determine extents of a roadway segment corresponding to the intersection leg, applying the intersection design criteria to generate corner geometry connecting between the roadway segments, and generating display signals for causing the geometric layout of the intersection to be displayed on a computer display.