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How do I activate the intersection lights when I am on a bicycle?

A. The intersection uses sensors in the roadway located in the center of the lane near the solid white limit line of the intersection to detect vehicles. These sensors are specifically designed and tuned to detect a bicycle. If you place your bicycle directly on top of the sensor, the traffic signal will detect your bicycle.

Some modern bicycles made from advanced composites or carbon fiber may not activate the sensor. The bicycle push button located at the intersection can be used to request a green light

For more information on bicycling at UCI, visit

How are speed limits determined?

A. The process for establishing speed limits is prescribed by state law. Roadway features such as crosswalks, driveways and sight distance are all considered when establishing a speed limit. These features are evaluated along with traffic volumes and driving habits of motorists traveling on that particular section of roadway.

How is the length of the green light decided?

A. The green light timing is optimized for daily traffic on campus. Occasionally, campus construction or special events can change traffic patterns and cause congestion. The department works with planners to forecast and adjust traffic plans to reduce traffic impacts as much as possible.

If there is excessive delay at a traffic signal, please contact

How is the length of the yellow light decided?

A. Yellow times are prescribed by state law (VC 21400) and managed by the California Department of Transportation. The timing is designed to best accommodate the needs of all types of vehicles, ranging from bicycles and motorcycles to passenger cars and semi-trucks.

For more information, see

Why are the red lights flashing on and off?

A. Flashing red or traffic signals that are off can result from emergencies, maintenance projects or special events. When you see a flashing red or traffic signal that are off, approach the intersection with extreme caution and treat the intersection as you would an all-way stop sign. Often times, a traffic director or police officer will be directing traffic at the intersection. Please give them your full attention and follow their instructions.

For more information on flashing red or dark traffic signals, see the California Vehicle Code at

How do I report a traffic signal that is not working properly?

A. If you notice a traffic signal that is not working properly, please contact the traffic management division at 949-824-0967 or email

How do you evaluate the inclusion of crosswalks at intersections? Why is it important to use them?

A. Pedestrian flow is carefully monitored and marked crosswalks are placed at areas that will best serve pedestrian safety. Marked midblock pedestrian crosswalks can cause an increase in pedestrian vs. vehicle collisions. In a marked crosswalk, a pedestrian will often enter the crosswalk assuming the motorist will see them and yield the right of way.

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UCI Transportation and Distribution Services
200 Public Services Building
Irvine, CA 92697-4525
Phone: (949) 824-7275
Office Hours: Monday - Friday 7:30 AM - 4:00 PM
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