Stopped and control delay relationship at signalized intersections under heterogeneous traffic conditions

Several types of delay can be measured at an intersection, and each serves a different purpose to the transport engineer. However, control delay is the primary measure of performance used in the latest edition of Highway Capacity Manual (HCM 2000) to define Level of Service (LOS). In the previous editions of HCM, stopped delay was used as the principal performance measure. Method of data collection for stopped delay is much simpler than control delay, and a better understanding of the stopped to control delay relationship could allow traffic engineers to choose the simplest data collection method without fear of corrupting their results by converting between delay types. Hence, an attempt was made in the present paper to develop such a relation from the field data collected at three isolated signalized intersections. From the analysis of the data collected, a simple equation was developed to estimate control delay from stopped delay.