The behavioral impact of an advertising campaign to promote safety belt use.

Workers at a drive-through handed a free large soft drink to any driver who pulled in wearing a seat belt. The team counted belt use during four phases: baseline, reward on, reward off, reward on again. They used an ABAB reversal design to prove the drink caused the change.

Observers stood near the exit and simply marked belt or no belt for every car. No personal data were taken. The setting was a busy commercial strip in Virginia, so drivers were regular commuters, not students or patients.

Seat-belt use jumped from a large share to a large share as soon as the free drink started. When the reward stopped, use dropped back to a large share. Turning the reward on again pushed use up to a large share. The pattern shows the drink, not chance, drove the change.

After the final reward phase ended, the researchers watched one more week. Belt use fell to a large share again, proving the incentive did not create lasting habits.

Reed (1991) extended the same idea to Dutch military bases. They paired small prizes with police checks and saw belt use rise from a large share to a large share. The gain stuck best with young drivers, showing that adding mild enforcement can stretch a short-term token effect.

Elba et al. (2018) used an ABAB design in a gym instead of a parking lot. Signs plus easy-to-grab wipes boosted equipment cleaning the same way the soft drink boosted belt use. Both studies show a quick reversal when the antecedent or reward disappears.

Dukhayyil et al. (1973) tested kids in a lab and found choice plus immediate candy kept them on task longer. Haring et al. (1988) used immediate soda with adults in cars. Together they show that fast, small, consumable reinforcers work across ages and settings.

You can see big, fast gains when you tie a tiny, wanted item directly to the target act. The catch: the item must be delivered right away and must stay cheap. Plan for the fade from day one—pair the reward with praise, then thin the schedule, or add prompts like Reed (1991) did. If you run community safety projects, think pop-up incentives plus signs or enforcement so the behavior has a chance to survive after the soda stops.