Reducing vehicle speed is among the most effective road safety strategies. We assess how a new policy in Russia that eliminates fines for driving up to 20 km/h above the speed limit has affected the prevalence of speeding. We measured speeds periodically in 13 districts of two Russian regions during 2011–2013 and analysed the effect of the policy using difference-in-differences to control for seasonality. We find that the prevalence of speeding was declining steadily but half of the gains since mid-2011 were lost immediately after the new policy. Overall speeding increased significantly by 13 percentage points (pp, 95% CI 4 to 19). Speeding more than 10 km/h above the limit increased significantly by 10 pp (95% CI 2 to 12), and extreme speeding increased but not significantly (1.7 pp, 95% CI −1.1 to 4.5). Road traffic injuries will likely increase in Russia unless speeding fines are reinstated.