Guidelines for the Use of Pavement Marking Symbols at Freeway Interchanges

Abstract

Pavement marking technology has advanced sufficiently to allow large multicolor symbols to be marked on the pavement. These symbols provide drivers with another source of information to help them make good navigation decisions. The objective of this research was to identify appropriate in-lane pavement marking characteristics for use near freeway interchanges. Two laptop-based surveys were conducted to evaluate driver comprehension, recognition time, and preference for different designs and applications. From the information obtained in these surveys, researchers developed the following recommendations for in-lane pavement markings near an interchange: (a) arrow and shield markings should be used in combination; (b) in simple single-lane exits (particularly traditional lane drop right exits), pavement marking symbols only need to be placed in the exit lane; (c) if in-lane pavement markings are used at complex interchanges (e.g., optional lanes, multilane exits), the markings should be applied to all lanes; (d) optional lane pavement markings should provide the same basic information as other lanes at that interchange (i.e., show both highway shields and an option arrow); (e) lane markings should not be staggered; (f) when all symbols are the same, they should be installed in a single line; and (g) the use of cardinal directions should be limited.