City of Houston LED Traffic Signal Upgrade Program Presented by: Jeffrey S. Weatherford, P.E., PTOE Sr. Assistant Director City of Houston Department of Public Works and Engineering

City of Houston Traffic Signal Background The City currently operates and maintains almost 2,500 traffic signals within the City Limits. The City currently operates and maintains almost 2,500 traffic signals within the City Limits. –This includes several hundred TxDOT signalized intersections Each signalized intersection has between traffic signal heads, depending on intersection size. Each signalized intersection has between traffic signal heads, depending on intersection size. This yields a total number of between 40,000 and 50,000 individual heads throughout the City. This yields a total number of between 40,000 and 50,000 individual heads throughout the City.

Current LED Vs. Incandescent Traffic Signal Usage Almost one-third of our traffic signals have been, or are being, converted to LED traffic signal indications. Almost one-third of our traffic signals have been, or are being, converted to LED traffic signal indications. –All remaining incandescent traffic signal indications use either 65 watt or 135 watt bulbs. –The split between the two sizes is roughly 50/50.

Current Energy Usage Every traffic signal head has at least one indication on at all times. Every traffic signal head has at least one indication on at all times. –The one-third of traffic signals with LED traffic signals use about 981,000 kW-hrs of electricity per year. –The remaining two-thirds of traffic signals with incandescent bulbs use roughly 29,450,000 kW- hrs per year. This is 30 times the energy used by the LED traffic signals.

Why the Difference? LED traffic signal indications use almost 90% less energy than a 65 watt incandescent traffic signal bulb. LED traffic signal indications use almost 90% less energy than a 65 watt incandescent traffic signal bulb. LED traffic signal indications use almost 95% less energy than a 135 watt incandescent traffic signal bulb. LED traffic signal indications use almost 95% less energy than a 135 watt incandescent traffic signal bulb.

What Happens to Our Energy Usage If We Convert to LED Traffic Signals? Our current energy usage for the combined LED and incandescent traffic signals is approximately 30.4 million kW-hrs per year. Our current energy usage for the combined LED and incandescent traffic signals is approximately 30.4 million kW-hrs per year. After a total conversion to LED traffic signal indications, we expect to use about 3.05 million kW-hrs per year. After a total conversion to LED traffic signal indications, we expect to use about 3.05 million kW-hrs per year. In other words, we would reduce energy use by more than 90%. In other words, we would reduce energy use by more than 90%.

What Will This Project Entail? 1. An Inventory of All Intersections: –How Many Traffic Signal Heads are there? –What is the Bulb Wattage? 2. All remaining incandescent traffic signals will be upgraded to LED traffic signal indications. 3. All remaining 8” traffic signal heads will be upgraded to 12” traffic signal heads to enhance safety and prepare the City for upcoming changes in national standards.

How Will the Project Be Paid For? Public Works and Engineering has worked with the Finance Department to fund the project with commercial paper and use the future energy savings to pay back the loan. Public Works and Engineering has worked with the Finance Department to fund the project with commercial paper and use the future energy savings to pay back the loan. –Estimated project cost: $18 Million –Anticipated Pay Back: 7 Years

Questions?