This report proposes a method [for Society of Automotive Engineers (SAE) Recommended Practice J2365] to estimate in-vehicle task times and reviews the related human factors literature. This method will be used to evaluate alternative driver interface designs and to check compliance with the 15-second task time limit specified in SAE Recommended Practice J2364 (Navigation Function Access While Driving). Application of this method will enhance the safety and usability of driver information systems. A review of the human factors literature (Kurokawa's dissertation, Levison's Integrated Driver Model, the NASA MIDAS software, the Integrated Performance Modeling Environment, etc.) revealed that there was no personal computer software available or hand calculation methods tailored for this purpose. Therefore, the approach taken was to extend the Keystroke-Level Model (popular in human-computer interaction) using data from automotive navigation studies for calibration. The resulting 11-step calculation procedure begins with identifying all major goals (e.g., obtain guidance) and subgoals for each task the user performs along with identifying the method used (e.g., the street address method without short cuts). Exactly how each step is carried out is then described using pseudocode. Next, the associated elemental tasks [reaching for a device, keying (cursor, letter, space, enter), mental activity, searching, etc.] and their times are determined. Those times are adjusted for driver age, and entered into a spreadsheet where they are totaled. Finally, times are checked for reasonableness and the task sequences are adjusted as needed.

  • Record URL:
  • Supplemental Notes:
    • This research was sponsored by the Society of Automotive Engineers.
  • Corporate Authors:

    University of Michigan Transportation Research Institute

    2901 Baxter Road
    Ann Arbor, MI  United States  48109-2150
  • Authors:
    • Green, P
  • Publication Date: 1999-7


  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 47 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00798836
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: UMTRI-99-17,, HS-043 128
  • Files: HSL, TRIS, USDOT
  • Created Date: Sep 1 2000 12:00AM