San Diego’s I-15 integrated corridor management system wins another award


A continually-evolving project in California that has been described as “having the potential to completely transform traffic management”, has won another award for its day-to-day ability to move traffic through one of the busiest corridors in the USA.

Having previously won the ITS America Best New Innovative Practice Award in 2013, the San Diego Association of Governments (SANDAG) Integrated Corridor Management System (ICMS) on Interstate 15 has just picked up the California Transportation Foundation (CTF) Award for Operational Efficiency Program for the second time in three years. This pioneering ICM project aims to operate and manage individual transportation systems as a unified corridor, including the highway network, toll lanes, the surrounding arterials, and the public transport network in the area. The I-15 ICMS is designed to optimize capacity and efficiency, reduce delays and obtain more reliable journey times, without the need for investment in additional infrastructure, such as building more lanes for traffic.

Going live in March 2013, and focusing on a 20-mile (32km) stretch of I-15 between San Diego and Escondido, the project introduced smart traffic management technologies and concepts never used before in the USA. The project’s pioneering Decision Support System (DSS) uses strategies such as network traffic prediction, online microsimulation analysis, and real-time response strategy assessment, to give system managers comprehensive awareness of the current and predicted future performance of the entire corridor. Rather than reacting to traffic conditions, managers can now anticipate problems before they arise and take preventative action using ICM strategies such as responsive traffic light synchronization, coordinated ramp metering, or bus priority on arterials.

The I-15 ICMS centers around the DSS, for which Spanish company TSS-Transport Simulations Systems provides the Aimsun Online modeling tool that uses live traffic data feeds and simulations to dynamically forecast future corridor traffic conditions, based on the current state of the network. Due in a large part to the success of the ICMS, in 2015 the US Department of Transportation (USDOT) added the SANDAG ICM network to the Dynamic Mobility Applications (DMA) Active Transportation and Demand Management (ATDM) Analysis, Modeling and Simulation (AMS) Testbed Project.

“Since last year we’ve made a lot of progress on the ATDM/DMA test bed,” said TSS principal consultant Matthew Juckes. “With an analysis plan in place, we are now developing the tools needed to model both the communications and functionality of connected vehicles within the platform, including intelligent network flow optimization and cooperative adaptive cruise control, with others on the short-term horizon.”

The system has been running in an automated stage since March 2014, taking automatic control of signals and ramps when recommended by the simulated evaluations. The most recent update is the introduction of 40 alternate route signs along the arterials to guide drivers through the surface streets from and to the highway during a diversion. This, in addition to newly enhanced local street detection coverage, continues to improve the quality of the system and its ability to improve mobility through the corridor.

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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).