Citation

Wohlschlaeger SD, Ullman GL, Dudek CL. Transp. Res. Rec. 1995; 1495: 9-16.

Copyright

(Copyright © 1995, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Licensed driver interpretation of the Manual on Uniform Traffic Control Devices (MUTCD)-approved and experimental transition symbols in a lane control signal (LCS) array is documented. The two symbols tested were the yellow X (MUTCD approved) and the yellow downward diagonal arrow (experimental). These two symbols were displayed in a scene depicting a three-lane freeway section containing one LCS array. The various LCS arrays were representative of typical LCS configurations for a median lane closure. Each transition symbol was tested in combination with two green down arrows and in an array containing one red X and one green down arrow. Overall, the study showed the yellow downward diagonal arrow to be interpreted more consistently and "correctly" given its intended use than the yellow X. Subject responses varied more for the yellow X than for the yellow downward diagonal arrow when a red X was included in the LCS array. In addition, subjects were more likely to interpret the yellow X in a manner that was considered "incorrect" given the intended use of the yellow transition symbols--a problem that was magnified when a red X was incorporated into the LCS array. Subject interpretation of the yellow transition symbols was also affected by the introduction of a red X into the LCS array. The most preferred subject interpretation of the yellow X and yellow downward diagonal arrow was the same when the transition symbols were displayed in an LCS array either with or without a red X. The meaning offered most frequently by subjects was "lane closed, blocked, or closing". The second most common interpretation of both the yellow X and yellow downward diagonal arrow varied somewhat, however. When displayed with two green down arrows "lane ends physically" was the second most frequent interpretation, whereas introduction of a red X into the LCS array altered subject perception and "lane is congested" became the second most popular meaning.

Record URL:
http://onlinepubs.trb.org/Onlinepubs/trr/1995/1495/1495-002.pdf

Language: en

Keywords

Automobile drivers; Traffic signals; Highway traffic control; Highway systems