Table 1.

Phase 1 treatment assignments and retention in phase 2

Sticker typePhase 1 recruitmentPhase 2 retention
Pure control2,09382%
Placebo1,75977%
Treatment stickers7,88573%
Total11,73775%
Individual actionCollective action
Treatment groupsPhase 1 recruitmentPhase 2 retentionPhase 1 recruitmentPhase 2 retention
Text only97173%97970%
Supportive (voice)1,00071%99872%
Consequence aversion (injuries)97475%98076%
Event aversion (crashes)99270%99172%
Total3,93772%3,94873%