The new Payson I-15 interchange will follow braided ramp design

March 5, 2019

The Utah Department of Transportation has given final approval for the anticipated new Payson I-15 Interchange to be designed using a braided ramps option.

A Record of Decision issued by UDOT approves the project team’s selection of braided ramps as the preferred alternative for the interchange out of several design options. The braided ramps will improve the existing interchange at Payson’s Main Street while constructing a new interchange about .7 miles northeast of the current Main Street interchange, according to UDOT’s website.

A new five-lane road, the Nebo Beltway, will connect the new interchange to State Route 198. Braided ramps — ramps that cross over each other — will connect the two interchanges. Main Street will be widened to five lanes at the interchange, and taper to its current configuration south of 600 North.

“Alternative C1 would provide a free-flow connection between the Main Street interchange and a new interchange connecting to the proposed Nebo Beltway Phase I. Braided ramps (i.e., ramps that cross over each other) would connect the two interchanges,” the record of decision states. “From the new interchange, motorists would travel on Nebo Beltway Phase I until it intersects with SR-198 at 2100 West, thereby avoiding and reducing congestion at Main Street and the existing interchange.”

That alternative was selected from among numerous other options because it would result in the lowest average daily vehicle delay in the study area, according to the record of decision.

“From a design and operations perspective, it would provide the combined benefits of two interchange connections and an optimal Nebo Beltway Phase I alignment,” the ROD states. The option also had the most community support, in part because it left cultural resources, including historic homes on Payson’s Main Street, untouched.

The braided ramps option was chosen because it was preferred after considering traffic operations and social and economic impacts.

For instance, one option would have had smaller environmental impact on wetlands, but would have relocated the interchange from Main Street, which could have the unintended consequences economically and socially reducing traffic volume to the businesses on Main Street, according to the ROD.

The purpose of the project is to improve traffic congestion and accommodate future travel demand.

“The existing infrastructure will not be able to adequately serve the projected transportation demands from a rapidly growing population in and around Payson,” the ROD states.

The project is not yet funded. Once funding becomes available, UDOT can move forward with final design, acquiring right-of-ways and construction.

More information on the project can be found at udot.utah.gov/paysoneis.