Taking a new turn: J-turns rise in esteem among highway engineers
On the topic of highway safety, Victor Lund offered up this tip of his trade earlier in the month: "Hope," he said, "is not an engineering strategy."
A traffic engineer with St. Louis County based in Duluth, Lund is not alone in his thinking.
Calling on a move away from tradition, the people who design our roads are increasingly taking a data-driven approach. Described by sources as once tending to be reactive, engineers are analyzing data in the name of preventing crashes.
In some places that profile as merely risky, they're calling for the installation of low-cost safety measures, such as chevrons around curves where there have been no previous crashes.
For more-dangerous locations, the Minnesota Department of Transportation is among the entities using what are being called "innovative treatments" — improved roadway alignment, widened/paved shoulders, cable barriers, etc. — that have come through years of experimentation both locally and nationally to gain proven crash reduction records — sometimes at a fraction of the cost of past alternatives.
A trend at the center of the data wave is the increasing use of the J-turn.
The J-turn is officially known in Minnesota as a "reduced conflict intersection" — a compact set of U-turns at an intersection along a four-lane highway that serves to eliminate the statistically riskiest crossing maneuver in driving: moving across all four lanes of a divided highway.
The maneuver is found mostly on rural highways, and is notorious for introducing the possibility of right-angle, or T-bone, crashes. The crashes occur when a crossing vehicle encounters high-speed traffic from either direction.
"Right-angle crashes are the ones that are killing people," Lund said, calling it the second-most-common deadly crash behind the sort involving a single vehicle leaving the roadway — often to strike a tree. "Our bodies aren't designed to withstand the physics involved in a right-angle crash."
Typically, the worst such crashes occur in the far lanes — which happens in about three-fourths of the incidents, sources said.
"Some people just don't look again once they make their initial yield at the median," said Greg Helgeson, a Wisconsin Department of Transportation regional traffic safety engineer based in Eau Claire.
The J-turn prevents a traditional crossing maneuver and forces the driver to take a right turn into the flow of traffic, before guiding the driver through a left-hand U-turn into the opposing lanes. Finally, the motorist is led back to the crossing, finishing with another, final right turn.
Though J-turns have been installed at fewer than 20 intersections on highways across Minnesota (12 total) and Wisconsin (seven), engineers with both states agree the number of J-turns is poised to expand.
"We're starting to fund more and more of these," said Derek Leuer, a MnDOT assistant traffic safety engineer based in St. Paul. "We have at least 20 planned and programmed in the next four-five years."
In Twig, a J-turn project has been agreed upon between county and state officials for summer 2019 at the intersection of U.S. Highway 53 and St. Louis County Highway 7. Between 2006 and 2015, there were 27 crashes at the intersection, giving it the worst crash history on the corridor of highway between Pike Lake and Eveleth. Ten of those were injury crashes — two of them resulted in incapacitating injuries — and the other 17 involved only property damage.
Despite the fact there were no fatalities, Lund said, "Something is wrong here. We have to do something."
Lund is among those from St. Louis County and MnDOT who will attend a meeting of the Grand Lake Town Board at 7 p.m. July 11 to discuss a project that has not been well-received by locals to date.
A petition registering opposition to the planned J-turn is being hosted in the Twig Store by owner Linda Sullivan. She's admittedly not hopeful to change the direction things are headed. But she cited a common refrain from business owners about using the J-turn as a traffic device, saying it will dissuade potential customers from visiting her store for the way it will force some customers to reroute using a maneuver that takes on average 30 seconds longer than the old way of doing things.
"One direction from Highway 7 won't be able to cross to the store (without a U-turn)," she said. "Who knows — maybe they'll go to Super One instead?"
Sullivan said engineers with the county and state have forgotten the proverbial little man.
"You can see a half-mile in both directions and there's been two deaths in 20 years," said Sullivan, who has owned the store for 17 years. "If there were 10 accidents a month, I'd say, 'Go for it.' "
The current estimated cost of the Twig project is $500,000, Lund said. While subject to change, the prospect of lower price tags is one of the features that engineers appreciate about J-turns. They spend a fraction of the cost compared to the gold-standard highway treatments and still get to say they "eliminate" the most serious and fatal crashes.
"It's something the Federal Highway Administration is promoting as a proven countermeasure," Helgeson said of the clout now inherent in the J-turn option.
A safer alternative to alleviate the risks at such crossings are complete interchanges with on and off ramps, sources said. But that's a lot of dirt to move and amounts to a $10 million to $20 million solution, they added.
"You obviously don't want to interrupt flow of traffic on the main road," Helgeson said, ruling out signals and roundabouts. "For possibly less than a million dollars, you get a 75 percent crash reduction (with a J-turn). That's a really good investment compared to a top-of-the-line bridge or interchange that gives you 85-90 percent crash reduction."
St. Louis County will be hiring an engineering consultant to assist with the design and preparation of the Twig project for bidding in the fall of 2018.
A J-turn in Cotton met with similar public distrust in 2012. In five years since, there have been seven crashes in the area of the Cotton J-turn; two were minor injury crashes and five were property damage crashes.
"Mostly (vehicles) hitting signs," Leuer said.
Since Douglas County opened a J-turn at the intersection of U.S. Highway 53 and County Highway B in 2015, there have been zero crashes in 18 months at what had been what Helgeson called a "problematic" crossing. A new J-turn farther south on Highway 53 at County Highway L is planned for 2019. At least two more J-turns are being considered in discussions of intersections in Helgeson's 20-county area of responsibility — those coming in Spooner and Minong.
"There is no one-size-fits-all," he said, "but J-turns are popular."