IDAHO FALLS, Idaho (KIFI/KIDK) - Unless something changes, traffic congestion will create complete gridlock in East Idaho within as few as 10 years.
Exponential growth in traffic along the US-20 corridor between Idaho Falls and Montana is the subject of a new Safety and Mobility Improvement Study commissioned by the Idaho Transportation Department (ITD). The study will also include U.S. Highway 26 and Interstate 15 with an emphasis on traffic between Idaho Falls and Rexburg.
Several studies by ITD and Bonneville Metropolitan Planning Organization (BMPO) have identified the interchange where I-15 and Highway 20 meet at exit 119 as a bottleneck and safety concern.
"There's so much traffic it ends up backing up onto the interstate where it encounters traffic that's traveling 65 miles per hour so there's a potential for a huge accident at that location," Idaho Falls Public Works Director Chris Fredericksen said.
The off-ramp heading north onto highway 20 toward the John's Hole bridge has the highest volume of any ramp along I-15 in Idaho. Some studies predict gridlock in 10 years if something isn't done.
"And is that really the right place to fix it?” asks Idaho Falls Mayor Rebecca Casper. “Is there enough elbow room there to fix it or do we have to consider a new exchange somewhere else?"
There are concerns about improving the current interchange.
"It's so compact in the fact that you have the interstate, the railroad and also the river and so in order to build that there are a number of structures and costs that are immense in order to build that," Fredericksen said.
One solution that's been looked at is a loop to bypass downtown, by making streets like Crowley Road, York Road, Shelley-New Sweden Highway and 81st North more like expressways, by removing some lights and crossroads.
In awarding the Safety and Mobility Improvement Study contract to Boise-based HDR Engineering, ITD provided results of a 2015 traffic study which identified 20 potential solutions to gridlock along the I-15/US-20 urban corridor.
The 2015 study analyzed 20 traffic solutions including a loop expressway on the outskirts of town. The outer loop would be bordered by 81st Street on the North, 65th Street on the South, Shelly-New Sweden Road on the West and Crowley Road on the East.
There are also proposals to improve the Highway 20 interchanges near Rexburg. During peak hours the traffic can be backed up all the way to Highway 20, blocking a lane of traffic.
"That's our number one priority is how do we move these vehicles safely around our community,” Madison County Commissioner Jon Weber said.
The Madison Rural Planning Organization has looked at several options and has come up with a favorite.
"We have recommended a diversion diamond interchange like the one they have in Chubbuck," Weber said.
Weber admits it could take years to get the state and federal grants needed to such an expensive project.
The Idaho Transportation Department's Public Transportation Office is asking for input on their draft Statewide Public Transportation Plan and six Local Coordinated Plans until November 29. You can view the plans HERE.