By Sandie Grassino
Anyone who has traveled the section of Missouri State Highway 141 at or north of the I-44 intersection knows that it can be a tedious process. The amplified congestion on 141 is because of heavy usage and too few lanes. But a new turn system is set to alleviate some of those travel woes.
According to David J. Simmons, who is the Project Manager for this MODOT Project, as well as the Design/Build Coordinator for MODOT statewide, has introduced a new turn system into metropolitan intersections with its inception along 141. This system is known as “J Turns,” ThrU Turns or “Michigan Left” turns. Their introduction in Valley Park mark their first usage in any metro area in Missouri, although the method has been used for years in rural areas of Missouri for the last decade, according to Simmons.
This new method is introduced via these intersections, according to Simmons, because this area has had a “high number of cross-over accidents with an at-grade intersection.” The installation of this new system, according to Simmons, will mark “lots of improvements here.” He also explained it wis the “first signal ThrU with signals used with a six-lane highway in Missouri.
The major problem in this area of 141 is the volume, according to Simmons.
“60,000 cars travel this area of 141 each day. About 17,000 take a left at Vance Road (in Valley Park) each day,” he said. He stated there have been at least 1,000 car crashes associated with those intersections within the past three years.
Back-up traffic in those left turn lanes, impeding the flow of forward traffic in the other lanes, seems to have been a culprit.
Simmons said that, as the Design/ Build Coordinator for this MODOT Project, he evaluated several bids for the project, with each one identifying a ThrU Turn design or a variation of it.
Now, with the ThrU lanes, the northbound drivers will pass their left turn destination, proceed to a dedicated left turn light standard, turn left when green, cross over the southbound drive lanes into a “wide” left lane, and ‘u-turn’ when able into the southbound lanes and eventually making a right turn onto Vance. Simmons explained that the length of the passage lane to the ThrU turn is positioned in relation to the specific intersection. For instance, since more cars take the left at Vance daily, that lane approaching the new ThrU turn was extended to accommodate the larger number of cars.
Simmons said that they have “observed improved northbound free flow during the morning rush hours.”
The southbound condition will not be fully completed until “mid-2018 when the interchange is completed.”