California driver licensing policy permits drivers who cannot pass a regular drive test or who have a driving related physical or mental condition to be referred for a special drive test (SDT). This test is failed only if the driver makes a serious maneuver error that results in a collision or that poses a direct hazard to other drivers or pedestrians. This scoring characteristic differs from that of the department's regular drive test in which subjects can be failed for making too many maneuver errors, even if the errors do not have a direct bearing on safety. In 1992 the Research and Development Section (R&D) within the California Department of Motor Vehicles (DVM) raised concerns related to the SDT referral process, scoring criteria, and guidelines for translating SDT performance into licensing actions. Subsequently, both R&D and the Driver Licensing Policy Unit initiated separate evaluations of the SDT program. This report presents the results of the first phase of R&D's study. Some of the conclusions in the study suggest the following: 1. The internal consistency reliability estimate is judged to be spuriously high and therefore is not considered a valid indicator of the SDT's true reliability. 2. The low percentages of SDT referrals and SDT fails who were recommended for a licensing action, or had a license restriction other than corrective lenses imposed either before or within 1 year after the SDT referral, indicates that available treatments for incompetent drivers are underutilized. 3. The SDT is not effective in discriminating between accident free and accident involved drivers. 4. The fact that SDT referrals pose a much higher safety risk than do drivers of the same age and sex in general population brings into question whether a special assessment system should even be available to the former group of drivers. 5. The SDT program appears to reduce accident risk for drivers who fail the test but not for drivers who pass it.


  • English

Media Info

  • Features: Appendices; Tables;
  • Pagination: 31 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00726007
  • Record Type: Publication
  • Report/Paper Numbers: CAL-DMV-RSS-95-160,, HS-042 440
  • Created Date: Sep 24 1996 12:00AM