Frequently Asked Questions - City Engineering
Traffic Signals
Why do traffic lights take so long to change? Why does a signal change when no vehicles are present? What is being done to improve traffic signal timing and coordination? Why aren't signals put on a flash cycle late at night? How do I go about getting a traffic signal installed at an intersection? Why can't we get a left-turn arrow at a signalized intersection? If a traffic signal appears to be malfunctioning, who do I contact? When traveling on some streets, red lights are hit on a regular basis? Can't they coordinate them? Why isn't there enough green time at a signal to get the traffic through at some approaches? There is not enough pedestrian time to cross the street! The pedestrian signal does not work.Q: Why do traffic lights take so long to change?
A: The length of wait at a traffic signal depends on the signal cycle length and the amount of traffic. On major cooridors the cycle lengths are longer to accommodate higher volumes of traffic, to serve the greater number of separate traffic movements during the timing sequence and to accommodate much longer pedestrian crossing times. Overall, these longer cycle lengths provide more efficiency since they can move more vehicles through an intersection in a given amount of time. However, increasing cycle lengths may also cause some secondary movements longer delays.
For more information, contact or call 719-385-5966.
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Q: Why does a signal change when no vehicles are present?
A:
For most traffic signals in Colorado Springs the signal rests on the green light for the major street in order to serve the greater volume and switches to the side street upon demand. If the signal is sequencing to the side street for no apparent reason, it could be because of one of these situations:
- The video detectors are not operating correctly. Video detectors running 24 hours a day sometimes malfunction. In this case, the traffic signal falls into a fail-safe operation and sequences green light phases to the side street to ensure access. If you suspect that a video detector is not functioning correctly, please call 719-385-6720.
- The traffic signal has detected a vehicle that has subsequently made a right turn at the intersection. The detectors will recognize a right-turning vehicle sitting at an intersection for greater than 10 seconds. If this vehicle turns after this time the call for the green signal is still made. The same is true for pedestrian crossings. If the pedestrian activates the push button and crosses prior to receiving the walk light, the signal will still change its sequence.
With the exception of the downtown area, all traffic signals in the city have vehicle detectors for side street detection. Because of the high pedestrian volumes, the downtown signals operate under a pre-timed plan with the lights changing constantly to serve all approaches and pedestrian traffic.
For more information, contact or call 719-385-5966.
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Q: What is being done to improve traffic signal timing and coordination?
A:
The City is reviewing and revising traffic signal coordination timing on a continual basis. This includes the reviews needed to respond to concerns and requests about stops and delays along corridors. Comprehensive reviews are also performed along individual corridors every one to three years due to changes in traffic volumes, development, and signal operations.
In addition to this review, the City has initiated a strategic plan to be more proactive in improving traffic signal timings. To implement this plan, staff will focus attention to four key areas that include:
- improving signal coordination plans
- enhancing signal equipment
- initiating traffic benchmarking and reporting efforts
- bolstering public information and outreach activities
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Q: Why aren't signals put on a flash cycle late at night?
A: For your safety, the City does not put signals on flash late at night.
Many studies have indicated that collisions increase significantly at
locations with this type of operation even during periods when traffic
is light. As a safer alternative, the City's signals are equipped with
vehicle detectors and remain green for the major street unless crossing
traffic is detected. Also, many signals are released from
synchronization late at night so they will change almost immediately.
If a traffic signal is on flash, it is because there is a problem with
the equipment.
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Q: How do I go about getting a traffic signal installed at an intersection?
A: After receiving a request, staff carefully analyzes the accident
history, the intersection geometry, and the amount of vehicular and
pedestrian traffic at the intersection. In nearly all cases, the City
will apply warrants based on the Federal Highway Administration's
"Manual on Uniform Traffic Control Devices" that establishes minimum
criteria, or warrants, for the installation of new traffic signals. If
the location is warranted for traffic signals, the next challenge is to
find a method of constructing and funding the signal. A new signal
costs between $80,000 and $120,000 to design and construct, and an
additional $5,000 per year to maintain.
For more information, contact or call 719-385-5966.
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Q: Why can't we get a left-turn arrow at a signalized intersection?
A: Although left-turn arrows benefit turning traffic, they also increase
waiting times for other traffic and pedestrians using the intersection.
For this reason, certain criteria are used to ensure they are installed
at locations where they do not adversely affect other movements. The
criteria used when evaluating the need for a left-turn arrow signal are:
- how well the movement is operating without a left-turn signal.
- how much the left turn signal will increase waiting times to other traffic movements at the intersection
- the accident history for the movement
For more information, contact or call 719-385-5966.
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Q: If a traffic signal appears to be malfunctioning, who do I contact?
A:
For reporting signal malfunctions or to discuss a technical question about the signal's operation, call 719-385-6720.
All signals within the City are maintained by the Traffic Engineering Division. This includes traffic signals along major highways and interstate ramps. Other signals outside the City limits are maintained by El Paso County Public Works, Colorado Department of Transportation, and other jurisdictions in which the signal is located.
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Q: When traveling on some streets, red lights are hit on a regular basis? Can't they coordinate them?
A:
Yes, all traffic signals along major streets are coordinated in peak hours to minimize stops and delays. Our staff examines each corridor and designs a "best-fit" timing plan to address the circumstances. Our problem, simply stated, is that these streets cannot be perfectly timed due to varying traffic speeds, congestion, the distance between signals and the need to vary the amount of green time at each intersection.
While designing coordination plans for a one-way street is pretty straightforward, doing so for two-way streets is much more complex. Timing must be designed so vehicles traveling in both directions arrive at the intersection simultaneously. Additionally, when one considers traffic from the side streets, heavier bi-directional flows, and that the intersections are not uniformly spaced, it becomes clear that there are no perfect solutions.
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Q: Why isn't there enough green time at a signal to get the traffic through at some approaches?
A: The amount of green time programmed for each movement at a signal
varies by traffic demand. When there are shorter green lights it is
often because there is more traffic than the signal can handle, and the
signal is over its capacity. In these situations, the Traffic
Engineering Division attempts to time the signals to equalize delays
for conflicting movements. In general, increasing green time for one
movement requires decreasing the amount of green time for another
movement.
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Q: There is not enough pedestrian time to cross the street! The pedestrian signal does not work.
A:
For crossing signalized approaches, pedestrians need to push the push buttons to receive adequate crossing times. With the exception of the downtown area, the pedestrian push button is the only means of activating the "Walk" light to obtain the required amount of crossing time. Pedestrians need to know that the push button, in most cases, will not change the light immediately unless this phase is next in the signal operation's sequence.
With this activation, the "Walk" light will allow people to step off the curb and start walking across the street, as this symbol means it is safe to start crossing. The flashing "Don't Walk" is next and provides enough time for pedestrians who have started to cross the street to complete their crossing before opposing traffic is released.
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