Over a four year period from 2009- 2012, the City of Santa Rosa implemented a citywide Street Light Reduction Program to cut energy costs and lower green house gas emissions. This program did not involve traffic signals—only street lights were affected.
Cost Savings and Environmental Benefits
Street Light Reduction Program has resulted in an annual energy cost savings of approximately $320,000. This savings was achieved through turning off some street lights, equipping some with programmable photocell timers, and leaving some lights to operate throughout the night.
Reduced energy consumption from street lights has resulted in a significant reduction to the City’s carbon footprint. An estimated 1,000 tons of greenhouse gas emissions are reduced annually through this program. Additionally, ambient light levels have been reduced allowing for greater visibility of the night sky.
Criteria Used to Determine Which Lights Remain On
The following are the criteria used to determine which street lights would remain on and which would operate with programmable photocell timers. All other street lighting was turned-off as part of this lighting reduction program.
Street lights which REMAIN ON throughout the night:
- All street lights at signalized intersections
- All lighting directly adjacent to or incorporated with pedestrian activated flashing beacons or mid-block crosswalks
- Lighting within high pedestrian zones, such as Downtown
- One light will remain on, where one exists today, at all un-signalized intersections
- One light will remain on at key traffic safety locations where there has been a documented history of traffic safety issues
Street lights selected to operate PROGRAMMABLE PHOTOCELL TIMERS:
- Programmable photocell timers were installed on light fixtures along street segments where the elimination of all street lighting would be inappropriate.
Several academic studies have been published on the correlation between street lighting and crime. None of the studies make a direct correlation between increased street lighting and reduced crime. In fact some of the research indicates just the opposite, noting that the introduction of street lighting actually increased the occurrence of crime as perpetrators could monitor their actions without the use of flashlights or other lighting tools which could highlight the individuals’ presence. Street Lighting Projects- National Evaluation Program Phase I Report
There are however, other aspects of public safety that are enhanced by the presence of street lighting. Some of these other valid issues include: crossing intersections as a motorist, pedestrian or cyclist; identification of unusual or unexpected roadway features, such as tight curves, medians or traffic calming devices; and visual support of critical facilities such as hospitals and fire stations.