New J-turn, roundabout proposed for Ashland
MoDOT taking comments on safety improvement in region
Sunday, August 25, 2013
Mid-Missourians have until Sept. 5 to comment online about proposed changes to U.S. 63 in the Ashland area.
About a year from now, state Transportation officials expect Ashland-area residents and others traveling to and from Columbia to be getting used to using a new j-turn on southbound U.S. 63, at the south edge of town, and new roundabouts at the exit/entrance ramps at the U.S. 63/Routes Y and MM interchange.
MoDOT already has opened similar j-turns on 63 in Boone County, between the Columbia Regional Airport and the south end of Columbia and in Cole County along U.S. 54, between the Missouri 179/Route B interchange, at the south end of Jefferson City, and Eugene.
In each case, those j-turns eliminate grade-level highway crossings and are designed to make travel safer.
At Ashland, the plan is to close the U.S. 63 crossovers at Liberty and Peterson lanes, both south of the interchange.
“A typical at-grade crossing on a four-lane highway — similar to that at Liberty and Peterson lanes — can have as many as 42 ‘conflict points’ within the intersection,” Michael Dusenberg, MoDOT’s Central District transportation project manager, said in an email. “Each conflict point is a location where two vehicles can meet, which may result in an accident.
“Of the 42 conflict points, 24 conflict points are at locations that can result in serious or fatal accidents, such as right-angle or T-bone crashes.”
A j-turn provides an engineered U-turn, allowing motorists to reverse direction on a multi-lane highways.
It includes a deceleration lane on the left side of the driving lanes, then a space for the U-turn into the lanes heading in the opposite direction, then an acceleration lane so the driver can merge with the oncoming traffic at highway speeds.
The j-turn name comes from its shape — the deceleration lane usually is longer than the acceleration lane in the other direction.
Dusenberg said j-turns don’t eliminate all accidents.
“A j-turn, such as the one we are planning (at Ashland), reduces those conflict points to about 14 (from 24),” he explained. “The types of accidents that can result at those 14 conflict points are less severe, such as side-swiping or merging accidents.”
Engineers say that j-turns and roundabouts — which eliminate left-turns at intersections — are safer.
But, Dusenberg said, the other j-turns in the area “are still relatively new and no official before-and-after statistics have been compiled, yet.”
However, he added: “The accidents we are aware of that have occurred at these locations have been less severe than before.”
The University of Missouri currently is working on a j-turn study that will include comparison statistics for the U.S. 63 j-turns, Dusenberg said, and is scheduled to be completed at the end of this year.
And Missouri isn’t the only state that has j-turns on major highways.
“The state of North Carolina studied the effectiveness of j-turns and found they reduce fatal/injury accidents by 51 percent,” Dusenberg said.
MoDOT estimates the Ashland project will cost $1.7 million, Dusenberg said. “It is funded 100 percent from federal Open Container Funds,” which are used for safety projects.
People who want to comment on the Ashland project should link online to http://www.modot.org/central/major_projects/boone.htm.
A map of the project and a printable comment form are available on that Web page.
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