LEVEL OF SERVICE CRITERIA FOR MULTILANE HIGHWAYS CARRYING HETEROGENEOUS TRAFFIC

The Level of Service of a road generally describes the operating conditions and it has been defined in terms of density. When the length and speed of the vehicles in a traffic stream varies significantly, however, it has been, found that, the concept of occupancy, rather than density, is more appropriate to describe traffic concentration. The value of occupancy, however, changes with change in the detection-zone length. Also, the measure, occupancy is not appropriate under heterogeneous traffic conditions, as the traffic has no lane discipline and hence, it is necessary to consider the whole of the width of the road as single unit to analyze the traffic flow. Hence, a new concept named, 'area-occupancy' is proposed here. It was found that the concept of area-occupancy can be applied for any roadway and traffic conditions. Levels of Service criteria for multilane roads carrying heterogeneous traffic were developed based on the performance measures, speed, area-occupancy and V/C ratio.