Intersections occur when two or more roadways cross paths. The majority of accidents occur within intersections. Therefore, it is a priority for traffic engineers to minimize the risk to drivers by increasing safety within intersections. As a trade off, traffic engineers have to try to maximize the efficiency and mobility within the intersection. The delicate balance between moving traffic safely and efficiently has led to various types of intersection treatments.

The type of traffic control used within an intersection is determined by a variety of factors. There are strict guidelines outlined in the Federal Highway Administration’s Manual on Uniform Traffic Control Devices (MUTCD). The type of intersection traffic control is determined by a variety of factors including: traffic volumes, sight distance, crash histories, speed limits, and street classifications.

Uncontrolled Intersections

Uncontrolled intersections are within low traffic volumes, low speed roadways, typically in residential neighborhoods that rely on the Uniform Vehicle Code (UVC) to determine right-of-way.

In an uncontrolled intersection:

The driver of the vehicle on the left shall yield the right-of-way to all vehicles approaching from the right that are close enough to constitute an immediate hazard. A driver must yield to the vehicles on their right.

Occasionally, uncontrolled intersections need additional traffic control, but do not warrant the higher levels of traffic control such as stop signs, yield signs, traffic signals or roundabouts. In these special cases, various forms of “traffic calming” can be used to aid in the neighborhood traffic. To see more on traffic calming, click here.

To request a traffic and intersection evaluation, please complete this form.

The city of Helena does not own the majority of traffic signals in our city, most are owned and operated by the State Department of Transportation. The State is responsible for the timing and engineering of the lights, while we share a signal technician for maintenance and repair. For more information on this topic, click here.