Traffic Operations and Management

A number of adaptive control algorithms have been developed in the US and overseas. However, the practical implementation of adaptive control is limited especially in California. There is a need to develop adaptive control algorithms, evaluate their performance through a field test, and develop a deployment plan for possible Statewide application. The objectives of the study are identify and select the most promising of existing adaptive control algorithms, develop improved algorithm(s) as appropriate, conduct field tests on real-world arterials, and develop recommendations for deployment...

This report documents work accomplished during Fiscal Year 2005-2005 as a part of a research project entitled “New Approach to Bottleneck Capacity.” This project is developing an alternative to the traditional Highway Capacity Manual approach to capacity analysis in which capacity flow [either pre-queue flow (PQF) or queue discharge flow (QDF)] is related to a set of intervening variables, including the average time gaps in the critical lane (i. e., that with the highest flow rate) and the distribution of flow across the lanes, represented by the critical lane flow ratio (i. e., the flow...

The 58.5-mile long Highway 101 corridor from the Bay Bridge to the SR 85/US-101 interchange in South San Jose accommodates just over 2.6 million trips on an average weekday. Travel delays on the US-101 corridor over the 2012-2016 five-year period increased by more than 91% (an average delay increase of over 18% per year). Given that California’s economy recently grew to become the sixth largest in the world, this waste of time stuck in traffic ranks among the most consequential economic inefficiencies in the world; workers in this region produce about 15 percent of California’s annual...

Optimized Policies for Adaptive Control (OPAC) is a real-time demand-responsive traffic signal timing optimization algorithm for individual intersections. It was developed at University of Lowell under the sponsorship of U.S. Department of Transportation in the early 80s. OPAC distinguishes itself from traditional cycle-split signal control strategies by dropping the concept of cycle. In OPAC, the signal control problem consists of a sequence of switching decisions made at fixed time intervals. At each decision point the question is whether to extend or terminate current phase. Dynamic...