City of Fremont Citywide Battery Back Up System Installation Project

Cost: $500k+

Role: Project Engineer (PE) and Project Manager (PM)

Donya Amiri was City of Fremont's Transportation Engineer in charge of operating over 220 traffic signals. Given the fluctuation in power and regular PG&E outages in certain parts of the city, installing  battery backup units was essential to keeping the traffic signals in operations during a power interruption. Funds from existing traffic signal accounts were used to expedite the installation of over twenty battery back up systems and to reenergize 11 existing battery back systems. Key reasons why this Donya Amiri prioritized this unplanned project:

  1. Improving safety! By having more of our intersections equipped with operating and dependable battery backup system, the greater the chance of reducing collisions due to a dark intersection, equipment failure, saving Fremont Police Department and Maintenance staffing efforts in placing/removing 4-way stops, as well as ensuring smooth traffic signal operation during a planned or unplanned power outage.
  2. A competitive product in the market was first piloted and determined to outperform the high end system that was currently used by the City. The extra effort of getting competitors to come and present their product to the City and pilot their equipment during with a planned power outage, paid great dividends when the City was able to purchase a complete system for about $5k/system instead of $18k/system! Great saving for the city and major upgrade to the traffic signal infrastructure.  
  3. Over 20 of the busiest intersections that carry the highest volumes of vehicles and pedestrians now have battery backup systems that are reliable and fully charged to perform up to 8 hours.
  4. Safely transition an intersection that has a power outage from full color cycle to flashing red when the battery life reaches about 40% using Preemption 1 signal timing in the controller. This required signal timing changes in our central system, intersection controller, and special wiring inside the cabinet.

This project has been greatly appreciated by the community,  Fremont Police Department, Public Works Maintenance, and traffic signal maintenance contractor.