Pilot tests of a seat belt gearshift delay on the belt use of commercial fleet drivers.

This study evaluated a device that prevented drivers from shifting vehicles into gear for up to 8 seconds unless the seat belt was buckled. Participants, commercial drivers from the United States and Canada who did not consistently wear their seat belts, could avoid the delay by fastening their seat belts. Unbelted participants experienced a delay of either a constant 8 seconds or a variable delay that lasted an average of 8 seconds. United States drivers’ belt use increased from 47% to 68% (a 45% increase), and Canadian drivers’ use rose from 54% to 75% (a 39% increase). There was no significant difference between the fixed and variable delay schedules.