Aug 30, 2013

An OTREC project recently took an in-depth look at the travel-time and health-related effects of a new implementation of a state of the art adaptive traffic system.

Southeast Powell Boulevard is a multimodal urban corridor connecting highway US-26 through Portland, Oregon. The corridor is highly congested during morning and evening peak traffic hours. In October 2011, an adaptive traffic system called SCATS was deployed.

The primary function of SCATS, or Sydney Coordinated Adaptive Traffic System, is to mitigate traffic congestion. Using sensors (usually inductive loops) at each traffic signal, the system tries to find the best cycle time and phasing along the corridor as traffic demand patterns change.

In this integrated multimodal study, OTREC researchers looked at the corridor’s traffic speed and transit reliability, before and after the implementation of SCATS. In addition, a novel contribution of this study was to study the link between signal timing and air quality.

To determine the impact of SCATS on traffic and transit performance, researchers established and measured performance measures before and after SCATS. The researchers used data provided by TriMet, Portland's transit authority, to compare transit times before and after SCATS as well as traffic volume data from two Wavetronix units that were installed by the City of Portland; these units collect traffic counts, speeds and classifications. For the air quality study, TriMet also...

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