Dimming the dipped headlamp beam is a simple and effective method of providing a 'town beam' for use on a vehicle travelling in well-lit streets at night, a manual form controlled by the driver first being produced in the 1960s. The report describes the design and construction of an alternative system for automatically controlling the intensity of the dipped headlamps according to the quality of the street lighting. Results of large scale trials of the automatic system when fitted to post office and police vehicles are given, particular attention being paid to driver acceptability and system reliability. The results of the trials showed that many drivers were not satisfied with the performance of the automatic system; the failure rate of the units was also found to be unacceptably high. It is concluded that as it is not possible to modify the units to overcome drivers' objections at present, work on the automatically controlled version of the 'town beam' should be discontinued for the time being and that work on the 'town beam' which is continuing, should be concentrated on the manual system, controlled by the driver. (Author/publisher)
Samenvatting