Abstract
Experience with flexible traffic light control in Hamburg is recorded. It appeared that during the installation period more planning was required than with conventional relay installations, and four times as much changes had to be introduced. Improvements in traffic flow and in the number of road accidents were observed. Some operational characteristics of flexible and fixed are compared. Both continuous change of programmes and fixed weekly automatic programmes are possible, both with hardly a manual intervention needed. In practice, favourable results by road users were experienced in travel time, waiting time and the number of stops. Reductions in travel time are tabulated. A decrease in the number of accidents was also observed.