Citation

Hanscom F. ITE J. 2010; 80(7): 40-44.

Copyright

(Copyright © 2010, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

Several innovative signing and pavement marking options for roundabouts were included in the 2009 Manual on Uniform Traffic Control Devices. These options were designed to assist drivers in the navigation of roundabouts. The devices include fishhook roundabout–entry pavement markings, curved-stem arrows on advance guide signs, and specific central island sign characteristics, including black-on-yellow warning and black-on-white chevron regulatory signs. This paper describes a human factors study that was conducted to evaluate driver understanding of the devices. A total of 28 combinations of advance guide sign and pavement marking alternatives was tested in a laboratory setting. Subjects viewed sequential highway scenes illustrating advance guide signs and roundabout entry-point scenes with tested pavement markings. The procedure elicited subject responses concerning which roundabout inner-circle lane was appropriate to reach an intended destination and confidence in their choice decisions. Findings show that although conventional advance signs with conventional roundabout-entry pavement markings were generally effective at eliciting correct inner-circle lane choices, the combination of the curved-stem advance sign and the fishhook marking was associated with the highest percentage of correct choices. However, the curved stem advance guide sign is not recommended when no roundabout entry pavement marking is provided. Good roundabout design geometry rather than the presence of roundabout-entry pavement markings alone is the best deterrent to wrong-way movement in roundabouts.