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Bangerter Corridor, Salt Lake County, UT 

DISPLACED LEFT TURN INTERSECTION 

FHWA-SA-14-060 Updated July 2020

THE PROBLEM 

The Bangerter Highway 

corridor had a high crash rate 

and heavy delays. At some 

intersections, 25 percent of 

the signal time was devoted 

to left turns onto the minor 

roads, impeding both through 

traffic and traffic on the minor 

roads. 

THE SOLUTION 

Installation of two legged and 

four legged DLT intersections 

at seven locations on the 

corridor to help alleviate 

congestion and improve flow.

THE OUTCOME 

⯀ Commute time along the 

corridor has been reduced 

by 3 1⁄2 minutes. 

⯀ More than 800,000 gallons 

of fuel have been saved. 

⯀ Construction costs have 

been reduced by $20 40 

million. 

⯀ Crashes within 3⁄4 of a mile 

of the initially treated 

intersection have been 

reduced by as much as 60 

percent. 

⯀ Capacity along the corridor 

has increased by as much 

20 50 percent, depending 

on the intersection. 

CONTACT 

Jeffrey Shaw, P.E.

FHWA Office of Safety

202.738.7793

jeffrey.shaw@dot.gov

Mark Doctor, P.E.

FHWA Resource Center 

404.895.6210

mark.doctor@dot.gov

CORRIDOR LOCATION 

40°41’47.8”N 111°58’51.4”W 

Background 

Bangerter Highway is a major north-south corridor stretching from Salt Lake International 

Airport in the north to an interchange with I-15 in the south. Prior to construction of a series 

of Displaced Left Turn Intersections (DLT), also known as Continuous Flow Intersections 

(CFI), Bangerter Highway experienced high crash rates and heavy delays. 

Challenges 

Utah DOT’s (UDOT) primary challenge along the this corridor was congestion. At some 

intersections, 25 percent of the signal time was devoted to left turns onto the minor roads,1

impeding both through and minor road traffic. This challenge was compounded by a high 

crash rate. Between 1994 and 2003, the intersection of Bangerter and 3500 South alone 

experienced 618 crashes, an average of more than one crash per week.2 

Approach 

UDOT examined several ways to treat the intersection of Bangerter and 3500 South— both 

to reduce congestion and to improve safety. A VISSIM simulation comparing a DLT to no 

changes at this location showed significant operational improvements with the DLT. UDOT 

installed the DLT at Bangerter and 3500 

South and observed how it improved both 

traffic flow and safety at the intersection. 

In addition to the decreased commute 

time of nearly 4 minutes and a 60 percent 

reduction in crashes near the intersection, UDOT found that the DLT could be 

constructed for about 1⁄4 the cost of a 

grade-separated interchange.3 This motivated UDOT to install an additional six DLTs 

along the corridor. 

Results 

Choosing to apply DLTs saved the state hundreds of millions of dollars. Each new DLT 

intersection cost between $6 and $8 million. Freeway-like, grade-separated interchanges 

would have cost $30 to $50 million each and required the re-location of numerous local 

businesses.4 

In addition to cost savings, capacity along the corridor has increased by as much as 20 to 50 

percent, depending on the intersection.5 Safety also has improved, with crashs declining by 

60 percent at some installations.6 Air quality improvements include emissions reductions 

that save more than 800,000 gallons of fuel previously wasted during congestion-related 

idling. Pedestrians and bicyclists also benefit from improvements such as overhead pedestrian walkways, signalized crosswalks, refuge islands, and bicycle lane striping. 

Left Turn Crossover at Bangerter Highway and 3500 South 

Source: DLT Case Study Video FHWA-SA-14-059 

1 Lee Davidson, “Unusual Utah intersections improve safety, save money,” The Salt Lake Tribune, November 19, 2012. Available at: 

http://www.sltrib.com/sltrib/news/55293779-78/bangerter-south-million-cfis.html.csp

2 Wayne D. Cottrell and Sichun Mu, Utah Intersection Safety - Recurrent Crash Sites: Identification, Issues and Factors, “Chapter 6. Study Intersections,” Table 6.5, https://www.semanticscholar.org/paper/Utah-Intersection-Safety%3ARecurrent-Crash-Sites%3A-Cottrell-u/4753ca9386a82e91f59d95885109b0084339e6f3

3 Interview with Eric Rasband, Salt Lake City, UT, October 10, 2013. 

4 Davidson, “Unusual Utah intersections.” 

5 Interview with Eric Rasband, Salt lake City, UT, October 10, 2013. 

6 Davidson, “Unusual Utah intersections.” www.safety.fhwa.dot.gov

This Fact Sheet is a companion to the Video Case Study (FHWA-SA-14-059)