U.S. 20 interchanges save lives
The interchanges on U.S. 20 between Idaho Falls and Sugar City have helped reduce serious-injury crashes despite increased traffic levels and higher speed limits.
Serious-injury crashes have dropped from an average of 80 in 2000 to 38 in 2015, and average annual fatalities have dropped from two to zero, with no fatalities from 2011 to 2014.
The Idaho Transportation Department has constructed six interchanges along U.S. 20 since 2000. They include the Sugar City-Salem (Exit 338), Driggs-Jackson (Exit 339) and County Line (Exit 318) interchanges constructed in 2001, the St. Leon (Exit 311) and Hitt (Exit 313) interchanges constructed in 2004-2005, and the Menan-Lorenzo (Exit 325) interchange constructed in 2010-2011, pictured above.
In connection with the construction, the transportation department has closed 13 at-grade, or direct, intersections along the 34-mile stretch of the route and will close five more intersections when building the Thornton interchange next year. Interchanges enable smoother access on to and exit from busy highways, improving traffic safety.
Since 2000, the average number of vehicles on the four-lane divided highway increased from 10,000 to 21,500 per day, and the speed limit increased from 55 mph to 65 mph.
"Building interchanges and eliminating at-grade accesses has minimized points of conflict for through and local traffic, furthering safety and mobility for motorists," said ITD District 6 Engineer Kimbol Allen. "Constructing the Thornton interchange will enable us to close five more dangerous crossings, further reducing conflict points."
The transportation department will advertise for bids to construct the Thornton interchange in November. Construction is scheduled to begin in the spring.