Abstract
Speed-flow relationships are investigated downstream of a queue and within the queue to identify capacity flows and the effects of formation of an upstream queue on speed and flow. Data were obtained from the Queen Elizabeth way in Ontario, Canada, on a level three-lane section of freeway. Results show markedly different shapes for the speed-flow curves in the queue and downstream. This result calls into question efforts to develop general speed-flow curves for specific facility types. In a bottleneck downstream of the queue, capacity was found to be approximately 2,300 passenger-car units per hour per lane. Queue formation had no effect on these flow rates but did affect observed speeds.