The Metro's first diverging diamond interchange delivers on its promise of improved safety. So far there have been no serious accidents there.
Superior’s Director of Public Works Alex Ariniello says the interchange has greatly improved safety for drivers, bicyclists, and pedestrians at U.S. 36 & McCaslin Boulevard. During the first year of operation, there have been zero injury accidents, and non-injury accidents have decreased an impressive 36-percent. Previous traffic patterns required vehicles to cross oncoming traffic to access either U.S. 36 or McCaslin Boulevard, leaving drivers vulnerable to serious t-bone type accidents.
The old interchange saw roughly two accidents each month. With the new diverging diamond design, which incorporated fewer conflict points and slower speeds, there were only 18 crashes at the intersection in 2016, all low severity, rear-end or sideswipe crashes with no injuries. In addition to improved safety, the diverging diamond design has saved taxpayers roughly $25 million dollars. The 2009 Colorado Department of Transportation Final Environmental Impact Statement, recommended a 9-lane bridge and related improvements which would have cost upwards of $40 million dollars. Today’s alternative diverging diamond design, including the bus ramps, arch, walkway and bike lanes, cost approximately $14 million. “I’d call these numbers not only exciting but refreshing,” says Superior Mayor Clint Folsom. “Not only did we save our residents millions of dollars, but we made our community a safer place at the same time, that’s a huge win in my book,” the Mayor concludes.
When the planning process started in 2011, there were only a handful of diverging diamond interchanges open in the United States, with the safety benefits largely theoretical at that point. Today there are more than 80 operating in the United States.