New data from the Utah Department of Transportation (UDOT) indicates that accidents at the intersection of 3500 South and Bangerter Highway in Salt Lake City have decreased by 60 percent since a continuous flow intersection (CFI) design was implemented in 2007. The department will continue to monitor the data as it begins planning the installation of four more CFIs in 2013.
The intersection in question is one of seven installed along Bangerter Highway in the last five years; it is the only one, however, that has been operating long enough to produce reliable three-year averages for accident data.
The unique design allows drivers turning left off of Bangerter to enter special turn lanes well before they reach the intersection. From there, a signal guides vehicles into a new set of extreme far left lanes allowing turns onto crossroads while through-traffic on Bangerter proceeds forward simultaneously.
UDOT data also shows that the 3500 South CFI saves commuters an estimated $6.1 million and 800,000 gallons of gasoline annually. From the construction side, CFIs cost between $6 million and $8 million to build, as opposed to $30 million to $40 million for a traditional grade separation interchange.