The Bannock Transportation Planning Organization (BTPO) has started a study to determine the current and future operating conditions of key un-signalized intersections within the City of Chubbuck, the City of Pocatello and Bannock County.
In 2020, BTPO began the process of updating the traffic impact study guidelines for the region. Traffic impact studies evaluate the impact of a specific development on a specific location. This type of analysis does not show the cumulative impact of all future developments over time.
The Un-signalized intersection study will analyze the cumulative impact of the region’s growth patterns on each of the 34 study intersections over the next twenty-five years. The study will determine which intersections do not meet service standards in 2045.
The study will provide local governments information they need to plan for improvements or identify alternatives to reduce the impact of growth on the study intersections.
Un-Signalized Intersection Study Process
BTPO is beginning the data collection process. Over the next several months, traffic data, crash data, and intersection layout for the 34 study intersections. BTPO is using a camera to record the intersection’s traffic activity over 13 hours. The number of vehicles and their action (turning or going straight) are grouped into 15-minute intervals.
Pneumatic road tubes will be set at each intersection for 48 to 72-hours. This data provides the total daily traffic volumes.
Each intersection will be evaluated to determine the types of traffic control devices needed and the level of service.
Traffic Signal Warrant Analysis Traffic signals are installed to improve the safety and operations of an intersection. The study will focus on four traffic-related criteria used to determine if a traffic signal should be installed.
Four-way Stop Analysis
The four-way stop analysis shows if the intersection’s traffic volumes might require a change from a stop-controlled intersection to a four-way stop or roundabout.
Level of Service
Level of service is a measure of average vehicle delay due to congestion or a traffic control device. The region has a Level of service standard that intersections should meet.
The summary provides a listing of locations that meet the signal warrant or four-way stop analysis. The report will list the intersections not meeting the Level of Service criteria in 2021 and 2045.
The City of Pocatello, City of Chubbuck, Bannock County, and BTPO will use the study to identify and plan for needed improvements at the intersections over the next 24-years.