Abstract
LOS concept is very important in highway system management which contains planning, design, maintenace, and replacement. For example highway intersection is designd so thatquality of service for road users may be a desirable state. This paper discussed measures of LOS and thresholds of LOS classification should be determined depending on the objectives which LOS concept will be applied, and a few critical points based on some traffic flow performance may be a proper threshold value of LOS not only theoretically but also accountably.
