THE EFFECT OF INCREASED POLICE ENFORCEMENT ON THE A1

The test concerning the effect of increased police enforcement on traffic flow characteristics and accidents described in this report was carried out during the years 1970-1972. Experimental and control sections of rural highways have been used in a before period, an experimental period with increased enforcement on the experimental highway, and an after period. Each period consisted of one year. The main result was that it was not possible to detect any changes in speed, in the observance of priority rules, or in the overtaking pattern which could be ascribed to the intensified police patrolling. The analyses of traffic accidents with personal injuries showed that there had not been any changes in the number, type of severity of the accidents on the test section during the test period which could be ascribed to the increased enforcement. This result must be assessed in the light of the fact that interviews with road users during the test seemed to show that the patrolling intensity had been too low to be observed by most of the road users as being greater than usual, although the patrolling intensity actually achieved in the experimental period was about three times as high as the previous intensity on the experimental highway. /TRRL/