Issaquah advances ITS work; feasibility study set for adaptive traffic signals

Transportation Engineering Manager John Mortensen updated the Mobility and Infrastructure Committee on the City of Issaquah—s work implementing the city—s Intelligent Transportation System (ITS) plan, describing hardware upgrades, staffing gaps and a staged evaluation of adaptive traffic signal control.

Mortensen told the committee the ITS plan, approved by the City Council about two years earlier, sets a mission to “improve safety, health, security, and movement of goods, services, and people for all modes of transportation” and established six goals that include improving safety, providing traveler information and integrating ITS with regional partners.

The administration—s assessment of existing conditions found that roughly half of the city—s ITS and signal-control devices had reached the end of their useful life; the communications network operated at about 10% of the speed needed to support proposed devices and lacked redundancy; many field devices could not send centralized performance data; and staff time was consumed by reactive repairs, producing substantial overtime costs. Mortensen said those findings informed a plan to move from a reactive system to a managed system and, ultimately, an optimized signal…