Drivers were observed and questioned and their responses were measured as they unexpectedly came upon "Do Not Enter"signs while "driving"in the Driving Simulation Laboratory. Red and white signs elicited an earlier response than did the Black and white signs, and more drivers response correctly to the red and white sign and more drivers responded correctly to the red and white signs. This finding was cross-validated by tests at another location. A second set of signs (in addition the "Do not enter) was tested at the second location. Results at this writing are not conclusive regarding the relative "noticeably" of the four different messages and additional testing is underway. Preliminary evaluation was made of the appearance of lane-line arrowheads painted on every fourth dashed line of an otherwise standard lane marking. The arrowheads were oriented in the direction of normal flow, so that a wrong-way driver would encounter a series of arrows with their points facing him. This particular type of lane-line arrow marking was judged not sufficiently noticeable to alert a wrong-way driver. Observations were made of several styles of pavement marking arrows. When approaching them from the pointed end, as a wrong-way driver would in attempting to enter an off-ramp the standard arrows (which originally were developed as directional guides) are not a detectable as two slightly different styles.
Abstract