An alarm device giving drivers warning of road markings has been tested. The purpose of the device is to give the driver an acoustic warning when passing the edgeline or centre line, thus making him/her observant of the fact the he/she is leaving the proper lane. The alarm system has been tested with respect to sensitivity and reliability. The device is designed to be activated by road markings which fulfil the demands on optical properties issued by the Swedish Road Administration. Furthermore, it must be reliable so that false or failing alarms are minimized. The results show that physically the alarm device operates satisfactorily; edgelines of centre lines with good optical properties are registered without exception. False or failing alarms are rare. Correct but undesired alarms do, however, occur expecially in built-up areas. The suggestion is that the device should be supplemented, making it speed-dependent; below a given speed the alarm will not be activated. The number of undesired alarms would then be reduced considerably. (A)
Abstract