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New, coordinated signals to help speed journey
in Pocatello and Cubbuck

Motorists traveling on major routes through Pocatello and Chubbuck should have smoother sailing and fewer delays at intersections as a result of a significant upgrade to the traffic signal system.

The first noticeable changes are taking place now, explains Dan Harelson of the District 5 office. ITD is partnering with the cities of Pocatello and Chubbuck to introduce the new traffic signal improvements.

The Pocatello signal system will be improved by interconnecting signals so they work better together. The upgrade includes installation of Light Emitting Diode (LED) signal lamps to increase energy efficiency and reduce maintenance, and modifying signal phasing to reduce congestion and improve motorist understanding.

Conduit to connect traffic signals were installed during recent construction projects on Yellowstone Avenue. Conduit will be added to other areas this spring. Fiber optic cable will be installed to enhance signal coordination throughout the metropolitan area.

When the project is completed, 33 intersections will be controlled by the brighter, longer-lasting LED signal lamps that consume about 90 percent less energy than conventional traffic lights.

Signal phasing will be changed by modifying cycle lengths to allow more traffic to flow through intersections on each cycle and to create more left turns opportunities, Harelson explains. The use of five-section signal heads that use innovative flashing yellow arrow displays will improve left-turn opportunities and are easier for motorists to understand, Harelson says.

A pair of the new five-section signal heads will be installed at Pine Street and Yellowstone Avenue to help motorists become familiar with their operation before 17 other intersections are converted.

The signal heads incorporate a flashing yellow arrow instead of a green ball to let motorists know they can safely make a left turn after yielding to oncoming traffic.

Green ball indications now are combined with a sign that says Left Turn Yield on Green Ball.

Federal Highway Administration (FHWA) research indicates that motorists understand the flashing yellow better than the green ball and sign combination.

The flashing yellow arrow displays being installed in Pocatello and Chubbuck are a continuation of the FHWA research. ITD will carefully monitor changes in accident patterns and traffic movement and report those changes to the federal agency.

The Pine Street/Yellowstone Avenue intersection received the new five-section lights this week (beginning Jan. 23). Other intersections will be converted in the next two months.