Citation

Kaestner N, Speight L. J. Saf. Res. 1975; 7(2): 56-66.

Affiliation

Kaestner, Noel: Willamette U

Copyright

(Copyright © 1975, U.S. National Safety Council, Publisher Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The effectiveness of driver improvement suspension was evaluated relative to four alternatives: no contact, a last chance warning letter, a probationary license, and a defensive driving course. Drivers were randomly assigned to these five conditions with the exception that the defensive driving course was available only in the three largest metropolitan areas of Oregon. The proportion of drivers in each group who were able to drive one full year without a moving violation or chargeable accident was compared among the groups. A final sample of 932 drivers records was analyzed. Drivers in the probationary license and DDC groups had significantly superior driving records in the follow-up year ended the suspension group. The probationary license also appeared to have a significant delay in effect on the occurrence of subsequent traffic citations or culpable collisions. The overall evidence argued for more extensive use of probationary licenses, and the defensive driving course. This conclusion does not imply the discontinuation of suspension as a driver improvement device, since it is likely that the effectiveness of both probationary license and the DDC might be at least partially due to the presence of suspension as a less desirable alternative.