DIRECT: Operational Field Test Evaluation Natural Use Study. Part 2. Driver211 Satisfaction in DIRECT Controlling for Reliability

摘要

One of the most difficult aspects of evaluating an operational field test is211u001eobtaining consumer response to products or services that are not market ready or 211u001eeven completely functional. The DIRECT (Driver Information Radio using 211u001eExperimental Communication Technologies) operational field test compared consumer 211u001eresponse to four new low-cost advanced traveler information systems (ATIS): 211u001eAutomatic Highway Advisory Radio (AHAR), Low Power Highway Advisory Radio 211u001e(LPHAR), Cellular telephone call-in, and Radio Data System (RDS/SCA). These 211u001esystems were compared to each other and to a control group of drivers using 211u001estandard radios and receiving commercial traffic reports. These systems were 211u001eselected because at little cost they could alert drivers to traffic conditions: 211u001eon-demand (versus periodic access to traffic information) specific to the routes 211u001e(versus area-wide information), and automatically interrupting if a new incident 211u001ewas identified. Nevertheless, because all of the systems evaluated in this study 211u001ewere limited-deployment pre-market implementations the subjects experienced a 211u001evariety of reliability problems. The problems ranged from receiving incomplete 211u001ereports of traffic problems to frequent radio interruptions with mundane traffic 211u001einformation. The evaluation presented this report addresses the drivers level of 211u001esatisfaction controlling for these reliability issues. The evaluation was 211u001econducted by setting the system reliability measures, based on driver survey 211u001eresponses, equal across each of the test systems including the control group. The 211u001eanalysis used a combination of principal component analysis (PCA) and regression 211u001eanalysis, reducing the evaluation to four intuitively appealing factors that 211u001eexplained most of the differences among the systems. The principal components 211u001escores from the PCA were used in the regression analysis to estimate the drivers 211u001esatisfaction.