J-turns, like roundabouts, are not universally popular among motorists.
Traffic engineers, however, insist they reduce serious accidents. And they have the data to prove it.
A number of J-turns replaced the traditional perpendicular, grade-level intersections on U.S. 63 between Jefferson City and Columbia since the fall of 2012. J-turns, like roundabouts, are designed to reduce the frequency of angle accidents (including T-bone collisions, which often are severe).
A recent University of Missouri study of five intersections where J-turns have been installed revealed no fatal accidents and a 50 percent reduction of injury accidents. The duration of the study varied between one and three years, depending on when the J-turns became operational.
And, to dispel the notion that J-turns only affect serious accidents, the study found J-turns reduced the number of all accidents by 35 percent.
"The numbers speak for themselves," said David Silvester, Central District engineer for the Missouri Department of Transportation (MoDOT). "We know J-turns are not popular with some drivers, but they are the exact kind of safety solution we need to use in many instances. This report proves they reduce traffic deaths and injuries, and they will continue to be a tool we use to make our roads as safe as possible."
Credit MoDOT and the university for not dismissing motorists' concerns. In an effort to understand those concerns, the agency and university conducted an online survey to evaluate the J-turns on Route 63 at Deer Park Road near Columbia.
Although respondents conceded the J-turns did not increase travel time, they registered concerns about: merging difficulty after the U-turn, insufficient U-turn radius to accommodate large vehicles, general driver uncertainty and improper use of acceleration and deceleration lanes.
Those concerns are not surprising. J-turns, and roundabouts, are relatively new; consequently, motorists must adapt. As motorists become educated about and familiar with these changes, criticism, like serious accidents, should diminish.
Silvester acknowledged the importance of education when he said: "We will continue to promote the safety benefits derived from using J-turns and work to inform drivers on how to properly navigate them."
J-turns represent another example of resistance to change, even when statistics show it is change for the better.