The main objective of task 4.2 in the EU-project PEPPER on traffic law enforcement measures has been to give a systematic review of evaluation studies on speed, drink driving and seat-belt enforcement by applying meta-analyses to assess the best estimates of the effects of enforcement measures on accidents and behaviour. The report separates between stationary speed enforcement using laser/radar, mobile patrolling, composite police controls with stationary/visible elements: and speed cameras. The overall accident-reducing effect is 18 % (-23: -13). Of these, mobile patrolling, mobile/hidden speed cameras and stationary speed enforcement "American type" (same unit measures, pursue and sanction the violator) do not have statistically significant effects on reducing the number of accidents. Visible/fixed speed cameras reduce the number of accidents with -34 % (-25; -42) while stationary and visible speed enforcement show a tendency in reducing the number of accidents of 11%, however insignificant (-22: +1). Concerning drink driving enforcement a distinction between patrolling measures and DUI checkpoints is justified. The former exhibits a significant effect on accidents by -8 (-12; -3), the latter somewhat stronger by a reduction of -15% (-18; -11). Finally, a meta-analysis of seat belt enforcement shows a significant increase in wearing rates of + 21 (duringperiod) and + 15 % (after-period).