DRIVER WORKLOAD AS A FUNCTION OF ROAD GEOMETRY: A PILOT EXPERIMENT

This experiment examined the relationship between road geometry, workload ratings, and predictions from Wierwille's workload model, and provided representative performance data for driving a simulator. Eight people drove the UMTRI driving simulator for six sets of roads (varying in sight distance from 150 to 1140 ft (46 to 347 m), each having a fixed sequence of five winding road segments of varying width (lanes of 7.5 to 12 ft [2.3 to 3.7 m]). The six sets were presented in a counterbalanced order. Traffic was not shown. The standard deviation of lateral position was 1.1 ft (.34 m), with drivers using more of the road as lane width increased (0.9 ft [.27 m]) for 7.5-ft (2.3-m) lanes to 1.4 ft (.43 m) for distance, except for the 150-ft (46-m) sight distance. In terms of predicting performance, the mean and standard deviation of speed were not correlated with workload ratings, Wierwille workload estimates, or other performance measures. The standard deviation of lateral position was correlated with workload ratings. These data suggest that use of the standard deviation of speed and lateral position as measures of driving workload merits reconsideration when workload is light and traffic is absent.

• Supplemental Notes:
  • Supported by a grant from the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  University of Michigan Transportation Research Institute

  2901 Baxter Road
  Ann Arbor, MI  United States  48109-2150

  Great Lakes Center for Truck and Transit Research

  201 UMTRI Building, 2901 Baxter Road
  Ann Arbor, MI  United States  48109-2150
• Authors:
  • Green, P
  • Lin, B
  • Bagian, T
• Publication Date: 1994-9

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 55 p.

Subject/Index Terms

• TRT Terms: Drivers; Driving simulators; Geometric design; Human factors engineering; Lateral placement; Standard deviation; Workload
• Subject Areas: Design; Highways; Planning and Forecasting; Safety and Human Factors; I21: Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00667573
• Record Type: Publication
• Report/Paper Numbers: GLCTTR 22-91/01, UMTRI-93-39
• Contract Numbers: DTOS88-G-0005
• Files: TRIS
• Created Date: Sep 30 1994 12:00AM