An evaluation of traffic information used by travelers in the Detroit area, in 2000, found that most drivers perceived commercial radio as "more reliable" than television or dynamic message sign information.
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United States

Commuter Perception of Commercial Radio Traffic Information

Summary Information

This paper describes traveler perception of commercial radio traffic information in the Detroit Metropolitan area. Two studies conducted in 1998 form the basis of this paper: the Driver Information Radio using Experimental Communication Technologies (DIRECT) operational test and an evaluation of Michigan Department of Transportation’s ITS Expansion project. The DIRECT operational test surveyed commuters working in downtown Detroit and the ITS Expansion project randomly sampled commuters living in southeast Michigan.

For the DIRECT operational test, a self-selected group of 147 commuters drove along the I-75 expressway between the north and northwest suburbs and downtown Detroit for eight weeks. Before and after participation, these commuters completed a detailed questionnaire comparing traffic information obtained via commercial radio to that accessed via telephone information systems, television broadcasts and roadside changeable message signs (CMS). Four factors; reliability, information content, information targeting, and human factors quality; were used to assess participant perception of system performance. Perception of system benefit was determined using two factors; affect quality and action quality. Of the 6,000 questionnaires mailed for the ITS Expansion project, 1,361 were completed and returned. These questionnaires were used to evaluate the usefulness of traffic information.

Results from both studies indicate that up to 89 percent of drivers rely on commercial radio for traffic information. Sixty-two percent of DIRECT respondents utilized telephone information systems to access traffic information. While approximately 33 percent of these drivers used television broadcasts or CMS to obtain traffic information. Commercial radio information was perceived as "more reliable" than television or CMS information. Television information content was viewed as "generally better" than radio information content, which was deemed "better" than that of CMSs. DIRECT respondents found "somewhat greater benefit" from radio information than television information and "greater benefit" from television information than CMS information. Approximately 50 percent of respondents to the ITS Expansion questionnaire found commercial radio traffic information useful "half the time or less." Fourteen percent "seldom or never" find radio information useful and 36 percent find radio information useful only "half the time."

Respondents to the DIRECT survey found all information systems equally poor in targeting traffic information. Twenty-six percent of ITS Expansion respondents believe regional traffic reports would be "extremely useful," while 62 percent think route-specific traffic reports would be "extremely useful." The paper concludes that the available traffic information services can be improved and that a personalized route-specific interrupt or "push" system could be a valuable and readily accepted complement to commercial radio traffic information.

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