The effects of a seatbelt-gearshift delay prompt on the seatbelt use of motorists who do not regularly wear seatbelts.

Van Houten et al. (2005) wired five drivers' cars so the gearshift stayed locked for 5–20 seconds until the seatbelt clicked. The team turned the delay on and off in an ABAB design to see if the pause alone would make non-users buckle up.

All drivers were adults who rarely wore belts. The device gave no alarms, fines, or prizes—just a brief wait.

Every driver buckled up as soon as the delay was active. When the delay was removed, belt use dropped back to near zero. Turning the delay on again restored 100% use.

The simple pause worked for all five people without any extra rewards or warnings.

Van Houten et al. (2011) later topped this result. Their accelerator-pedal lock forced 100% compliance from six commercial drivers and the effect lasted months, showing the delay idea can be made even stronger.

Dagnan et al. (2005) moved the same prompt concept outside the car. Posted signs at senior-community exits kept belt use about 25 points above control sites for four years, proving prompts can work at a community level too.

Handleman et al. (1980) warned that annoying buzzers get disconnected. The 2005 delay avoids that trap—it is silent, quick, and still works.

If you work with adult drivers—especially in fleet, delivery, or staff transport—ask mechanics to add a short seatbelt-to-shift delay. Five seconds is enough to turn chronic non-users into consistent bucklers. No stickers, lectures, or prizes are needed; the car itself cues the habit.