The research project had two sets of objectives, one for advanced, or adaptive, signal control systems and one for control systems integration. The primary objectives for the advanced signal control portion of the project were to (1) investigate adaptive signal control systems, such as SCOOT, SCAT, and OPAC, (2) evaluate the UTCS 1.5 generation signal system, (3) determine the applicability of, and interest in, advanced signal systems in the Puget Sound Region, and (4) provide coordination with local agencies on research efforts in arterial traffic management. The primary objectives for the control system integration portion of the project were to (1) determine regional needs and interest in integrating control systems, and (2) provide coordination with local agencies on research efforts in integrated control systems.
The researchers reviewed previous work in adaptive signal control and evaluated the Bellevue UTCS 1.5 signal system (no previous, documented evaluation of such a system was found in the literature search) to determine the applicability of adaptive control in the Seattle area. Then they developed a framework for investigating integrated control system needs and met with jurisdictions throughout the Seattle Metropolitan area to discuss adaptive signal control and control system integration.
The Bellevue UTCS 1.5 signal system has improved traffic flow on Bellevue's arterial network (volumes increased 17 percent with no significant changes in travel time), and the new system is easier to operate than the old system. Of the adaptive control strategies investigated, UTCS 1.5 and OPAC show the most promise for implementation in the Seattle Metropolitan area. WSDOT should investigate the possibility of OPAC demonstration or test sites in the Seattle area. Local jurisdictions are interested in improved coordination and some degree of system integration. The WSDOT should keep local jurisdictions involved in and informed of the upcoming freeway and arterial control system integration project. The corridor traffic management teams that will be established should take up the issue of control system integration.