About 140 of the traffic signal controllers in unincorporated Douglas County and Lone Tree use approximately 30-year-old technology that is prone to frequent clock drifting. Unfortunately, some traffic signal controllers’ clocks drift forward, and some drift back, causing significant timing differences between intersections. Drifts of even a few seconds create a ripple effect through the entire transportation network that leads to delays to every vehicle traveling along the roadway.
Douglas County Traffic will use Energy Efficiency and Conservation Block Grant funds toward the purchase of new next generation traffic signal controllers, a new central traffic signal system including software, hardware and new Ethernet communications equipment. Next generation traffic signal controllers maintain their clocks and can provide more advanced features to further increase efficiency.
Traffic signal synchronization has also been identified as a high priority for Douglas County residents who responded to a Douglas County 2008 Voter Opinion Poll (questions 43 and 50A).
Estimated Benefits of this Program:
Based on projections, it’s anticipated that a new traffic signal control system will result in a better synchronization process that will provide savings to the public. The savings will be in the form of increased fuel efficiency, decreased emissions and a decrease in waiting times at signalized intersections. Not including the value of their time, motorists driving through signalized intersections in unincorporated Douglas County and Lone Tree will see a total decrease in the fuel consumption on the order of 600,000 gallons per year ($1.5 million per year based on $2.50/gallon). According to estimating tools available on www.epa.gov, the resulting reduction of greenhouse gas (GHG) emissions equals 5,286 metric tons of CO2 equivalents per year.
Project Timeline:
Douglas County sent out a Request for Information (RFI) to select, purchase, and deploy the necessary equipment for this project. The RFI was sent out in March of 2010 and the selection was finalized in February 2011. Douglas County staff has installed the initial computer hardware and software and will begin to integrate the new field equipment in June 2011, which is expected to take six to nine months to complete.