FAQs

Q: If you remove the signal on 20^th, then won’t speeds on 20^th increase?

No. Removal of the signal should not increase speeds on West 20^th Avenue. Because the traffic signal essentially remains green nearly all the time, the signal has no impact on speeds. The traffic signal rarely turns red on 20th because so few vehicles use Oak Street, especially during the midday and overnight, which is when speeds tend to be higher. The studies showed that 85 percent of motorists on 20^th were traveling at 37 m.p.h. or under, with a few outliers late at night.

Additionally, traffic signals are specifically prohibited from being used for speed control by both the state and federal departments of transportation. Traffic signal use is designated specifically for assigning right of way movements when enough traffic volume is present from a secondary street to justify the need to stop traffic on a primary roadway. Unnecessarily stopping traffic on primary roadways can lead to violent rear-end collisions. If unnecessary stops become frustrating (or unexpected), this also increases the likelihood of motorists running a red light and causing broadside collisions.

Q: What is a traffic signal warrant?

A traffic signal warrant establishes minimum criteria for evaluating the need for a traffic signal at a specific intersection.

Q: In a traffic signal warrant study, what are the main factors that determine whether a traffic signal will be installed at an intersection?

Many factors are considered for the installation of a traffic signal. They include the location with respect to other intersections, traffic volumes, pedestrians, and safety. These factors are covered in the Manual on Uniform Traffic Control Devices (MUTCD).

Q: Is there a leading indicator or factor in determining whether an intersection warrants a traffic signal?

The primary consideration for the installation of a traffic signal traffic is traffic volumes. One warrant considers the highest eight hours of traffic during the day for the main and minor streets volumes while two others evaluate four hours of traffic and the single highest hour of traffic. The threshold of volumes per hour to satisfy a warrant are decreased when the speed of the main roadway is greater than 40 miles per hour.