Meaning and application of color and arrow indications for traffic signals. Paper presented at the 52nd Annual Meeting of the Highway Research Board HRB, Washington, D.C., January 1973.

A study related to the meaning and application of colour and arrow indications for traffic signals is reported. A controlled laboratory study, using both colour movies and colour slides, investigated 19 signal indications for their effectiveness in conveying their intended message to the driver. Based on the analysis of driver performance data recorded in a field study, a single indicator was recommended.