Maximum Toll on Utah's Interstate 15 Express Lanes Just Doubled

Express lanes, also called high-occupancy toll or HOT lanes when they allow carpools to access the toll lane at either no charge or at a discount, are popular with motorists who want a faster commute. But that popularity can cause oversubscription, as noted in a comprehensive post last April on the nation's growing express lane network.

 Oversubscription: Low tolls = low speed due to congestion

"That’s part of the problem in the Salt Lake City area, where Utah officials hoped to keep traffic in the Interstate 15 toll lanes at 55 mph," writes Daniel C. Vock, Governing's transportation reporter. "Tolls there have been capped at $1 [per zone], and average speeds at peak times have dropped to 31 mph. State leaders are considering doubling -- or even tripling -- the maximum toll."

"The primary purpose of express lanes, originally designed to utilize excess capacity, is to encourage people to carpool," reports Lee Davidson for The Salt Lake Tribune on the July 14 toll increase. "Use of those lanes is free to vehicles with at least two passengers."

The minimum toll for each of the seven payment zones [pdf], each about 10 miles, is a quarter. With the toll increase, the maximum increased to $2 during peak traffic times.

"This dynamic pricing approach will allow the Utah Department of Transportation (UDOT) to better manage traffic in the Express Lanes to ensure that carpoolers continue to see the benefit of speeds around 55 mph," according to UDOT's webpage on Express Pass, the electronic payment system for the I-15 Express Lanes. 

As always, carpoolers, buses, C Decal [clean fuel] vehicles and motorcycles are the first priority in the Express Lanes and may continue to use them without charge.

Quadrupling tolls considered

Apparently, policy-makers are skeptical that doubling the toll will do the decongestion trick, adds Davidson.

Sen. Howard Stephenson, R-Draper, chairman of the Revenue and Taxation Interim Committee, last year suggested “charging the maximum the market will bear” not only to reduce congestion but also to raise some money for highways.

Members of the Utah Transportation Commission also said a $2 maximum is not enough to reduce congestion and suggested making it $4 or more.

According to UDOT's press release on the toll increase, "During the 2018 Legislative session, lawmakers approved a maximum toll increase to as high as $4 to encourage more carpooling. UDOT opted to only increase the maximum to $2 per segment. The department will study the effectiveness of the increased fee before considering higher tolls in the future."

Jason Lee also reports on the toll doubling for Deseret News.

Additional information on the express lanes is available in the 219-page "I-15 Express Lanes Study: Phase II: Recommendations," [pdf] prepared for UDOT by Brigham Young University, Department of Civil and Environmental Engineering, published February 2015. From the executive summary:

There are three primary areas of recommendations for this research: 1) reduce violation rates along the corridor, 2) reduce volume in the ELs [express lanes] through an increase in tolls (and subsequent increase in speed), and 3) allow an increase in "C" decal vehicles once additional capacity is available.

Information on other approaches to reducing congestion in the express lane, such as restricting the toll-exemption for clean fuel vehicles, prohibiting solo-drivers to access express lanes when speeds drop, and dealing with the ongoing problem of cheating, was included in last October's post, also based on Lee Davidson's thorough reporting.

Hat tip AASHTO DTU.