For site design, it is recommended to follow the guidelines published by the Federal Highway Administration in the Manual on Uniform Traffic Control Devices (MUTCD). One common mistake we see on drawings relates to pavement markings at stop signs. In the example below, a single 4-inch yellow line has been painted perpendicular to the stop line to establish a centerline. The MUTCD indicates that a single solid yellow line shall not be used as a center line marking on a two-way roadway. Therefore, when a stop line is proposed, either a 4-inch double yellow line or no centerline markings should be proposed.