City of Aspen Signals Change with Control of Main Street Traffic Lights
Contacts: Carly McGowan, Project Manager, firstname.lastname@example.org or 970-309-2690, and Denise White, Communications Director, email@example.com or 970-920-5293
Aspen, Colo. – Friday, Nov. 5, 2021 – Timing is everything, and thanks to an intergovernmental agreement (IGA) between the City of Aspen and the Colorado Department of Transportation (CDOT), four Main Street traffic signals are now under local control.
Over the past few years, the City has partnered with CDOT to establish an IGA that allows Aspen to assume operations and maintenance responsibilities for four downtown traffic signals on Main Street at the intersections of Galena, Mill, Monarch, and Aspen streets. Under the agreement, CDOT is still financially responsible for funding the installation of battery backups at three intersections and an initial signal re-timing study. Aspen Street already possesses a battery backup.
“Our community and Council asked that the City’s traffic signals place more focus on the pedestrian friendliness of our downtown core,” said Carly McGowan, City of Aspen Engineering Project Manager. “CDOT does a great job at looking at a regional picture of vehicular movement and meeting standard intersection requirements, but we can now implement a local signal timing plan that embraces Aspen’s ideals.”
In taking over the operational responsibilities of these traffic signals, the City is able to respond to the community’s various traffic needs locally with daily oversight. Having control of these traffic signals also allows City staff to refine the timing plan over time to meet immediate needs and future ones.
The IGA became effective on Oct. 1, 2021, at which point the City’s Engineering Department started realigning the identified signals. The signals recently were re-timed according to a plan developed based on open-source travel data, in-field timing runs, and consultant Kimley-Horn’s recommendations from national standards. While the City’s initial timing plan highlights pedestrian safety for crossing, several changes are mutually beneficial for vehicular traffic. The initial plan resulted in:
- Coordinating and timing signals for morning and evening peak travel times. Community members, commuters, and visitors will now experience the “green wave” - adjacent traffic signals coordinated to provide a smooth traffic progression through this group of signals on Main Street. Morning traffic flowing into town will hit the “green wave” at Aspen Street and move through to Galena. Vice versa, evening traffic flowing out of town will hit a green light at Galena and take the wave through to Aspen Street. This timing aids in reducing stops and delays and also benefits pedestrians walking with the flow of traffic.
- Shortening traffic intervals from 80 seconds to 70 seconds. This timing alteration allows turning vehicles and pedestrians more opportunities to move through the given intersection.
- Programming signals with a Pedestrian Lead Interval (PLI) that gives pedestrians a three-second head start into an intersection before vehicles get a green light. This lead time provides pedestrians enhanced visibility to turning cars as they will be further into the intersection when cars moving in the same direction, which may be turning across the pedestrian route, can progress on their green light.
- Automating traffic cycles during daytime hours with fixed times, set for average conditions which change at predetermined time intervals. Because of this automation, pedestrians no longer need to push the “walk” button to activate the indicator during the daytime. Instead, the indicator will turn automatically whenever the pedestrian is allowed to cross.
However, the signals switch to traffic-activated during nighttime hours, so pedestrians will need to push the walk button between 10 p.m. and 6 a.m. to trigger the signal change. This evening switch allows pedestrians to adjust timing to optimize flow at the intersection and be responsive to their presence when vehicle traffic is reduced.
The City of Aspen’s Engineering Department will monitor how this initial timing plan works through early implementation to adjust the timing if needed. If you have questions about the project, please visit https://www.cityofaspen.com/257/Engineering or contact City of Aspen Engineering at 970-920-5080.