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Travel time (Traffic engineering) -- Oregon -- Portland, Traffic signs and signals -- Control systems -- Oregon -- Portland


Powell Boulevard is a prime example of a congested urban arterial; this roadway connects US-26 to downtown Portland, Oregon. This facility is one of the most congested arterial corridors in the Portland-metropolitan region. The City of Portland implemented the Sydney Coordinated Adaptive Traffic System (SCATS) in October 2011 in order to improve the operations of the corridor. SCATS has been implemented in a few US cities with mixed results so far. A properly calibrated system can have a significant positive impact on the performance of the traffic signals but its impact on transit performance has not been documented. This was the first SCATS implementation to integrate transit signal priority (TSP) and adaptive traffic systems in the United States and possibly in the world. The unique contributions of this study are: the evaluation of SCATS and bus transit performance utilizing permanent data collection stations monitoring traffic and transit signal priority. This work presents results and the methodology to evaluate transit performance with and without adaptive traffic signal control system on Powell Boulevard. The analysis examined the effect of SCATS on bus performance at the stop level and for the entire corridor by using a variety of performance measures. Statistically significant differences were observed in terms of travel times and SCATS related regression parameters. Overall, the travel time changes or improvements related to SCATS seem to depend greatly on the direction of travel and the time of day.

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