Physical policing

Physical policing has both advantages and disadvantages. The advantages are related to the fact that violators are immediately stopped by the police:

The violator is given immediate feedback
The police officer has the opportunity to explain why they are enforcing speed
If violators are stopped at a spot which is clearly visible to other drivers, the subjective chance of apprehension is increased

The disadvantage is that physical policing is far more labour-intensive and that it is virtually impossible to reach the same enforcement level as with speed cameras. Hence the objective chance of apprehension is much smaller. This is particularly true for speed enforcement by a patrolling police car. A patrolling police car follows the traffic stream and therefore has a relatively small chance of detecting a speed violator. If it does, it needs to follow that car for a sufficiently long time to determine the level of speeding reliably. Zaidel [72] criticizes conventional manpower-using methods of police enforcement of speed as being (too) selective, sporadic, inconsistent, and in the end, being rather expensive and ineffective.

In contrast to the foregoing criticism by Zaidel [71], there is evidence that even with time-consuming conventional manpower-using methods effective speed control over large areas is possible. A specific type of physical policing is the network-wide random enforcement or Random Road Watch (RRW). This is an enforcement resource management technique that randomly schedules levels of police enforcement with the aim of realizing long-term, widespread coverage of a road network. Violators are stopped by the police. Newstead et al.[47] evaluated an RRW programme in Queensland, Australia, applying a quasi-experimental study design and Poisson regression statistical analysis techniques. The estimated effects appeared to be largest on fatal crashes, with an estimated reduction of 31% on the roads included in the programme. The effects were smaller for less severe crashes. The effects became larger as time increased after the programme introduction. In the third year of the programme, savings, at state level, were some 12% on crashes of all severities and some 15% on the fatal road crashes. The cost benefit/cost ratio for the programme was estimated to be 55:1.