Siemens real-time adaptive traffic control technology reduces travel times in Ann Arbor


A year-long study on the effect of Siemens’ adaptive traffic signal control technology on a major corridor in Ann Arbor, Michigan, has shown a marked reduction in travel times along the route.

Deployed south of Michigan Stadium on a route that runs alongside Interstate 94, Siemens’ SCOOT (split cycle offset optimization technique) real-time traffic control system has reduced weekday travel times along the Ellsworth Corridor by 12%, and weekend travel time by 21%. The technology has allowed Ann Arbor to improve its traffic flow to make it easier for its 115,000 residents, which swells to 185,000 when school is in session, to move in and around the city. Last December, Ann Arbor was also the first to be named a Siemens center of excellence for intelligent traffic technology, a partnership that brings the latest technologies to help the city improve commute, game day, and the overall travel experience. Based on these results, the city has decided to deploy and operate SCOOT technology on all downtown intersections in the upcoming year.

Traditionally, traffic patterns are pre-programmed to manage flow. The Siemens SCOOT technology takes an adaptive approach, allowing sensors at an intersection to detect vehicle volumes and communicate with the city’s control center and signals to change traffic patterns in real-time. For example, the system tallies vehicles approaching the light and makes signal adjustments before a queue forms. This insight is especially valuable for special events that can draw thousands and increase the number of expected vehicles on the roads. In addition to improving traffic flow, the SCOOT system also helps Ann Arbor enhance its operations. According to officials, the system optimizes traffic flow and does so reliably, using automatic monitoring systems.

SCOOT began operating in Ann Arbor in April 2005, and was rolled out along most of the city’s main arteries. Its most recent deployment was along the Ellsworth Corridor. The city began the major data collection on SCOOT in December 2015, via a partnership with mobile analytics provider StreetLight Data, which conducted a study of the system employing GPS technology. Before implementing the SCOOT adaptive system, a driver had a 15% chance of navigating the corridor in less than three minutes. With SCOOT, the likelihood increased to more than 70%.

Siemens 12-year technology partnership with Ann Arbor has included the supply of intelligent traffic management software and hardware to provide insight into the city-wide system, and help mitigate congestion for hundreds of thousands of drivers. In 2012, Siemens specialized traffic controllers were included as part of the US Department of Transportation’s Ann Arbor test bed for connected vehicles. The specialized controllers transmit critical information to the ‘connected vehicles’ so they can make decisions in real-time to avoid crashes. Siemens has also provided versions of its Sepac controller firmware, and Tacticts advanced traffic management system (ATMS), that help the city’s traffic department plan, manage and control hundreds of signalized traffic intersections.

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About Author


Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).