Abstract
The purpose of this study was to investigate the need for improved signing at the beginning of no-passing zones. This investigation was concerned with the use of the standard white, rectangular `DO NOT PASS' sign and the yellow, pennant shaped `NO PASSING ZONE' sign. Each sign was evaluated on both sides of the roadway. Both signs were tested for visibility and effect on driver behaviour. Films, driver interviews and personal observations were used for this purpose. The results indicated that the sign on the left side of the roadway provided increased visibility over the one on the right.