Caltrans is installing permanent channelizers in a bid to further rein in motorists that are making last second merges to get into the eastbound 120 Bypass lane that splits off toward Modesto.
The permanent channelizers will start past the Main Street interchange and go all the way to where the lanes split.
The work will require nightly closures from Monday, Oct. 25, through Thursday, Oct. 28 from 11 p.m. until 5 a.m. of the eastbound lanes only. The westbound lanes will remain open.
The detour will take motorists off the freeway at Main Street and south to Atherton Drive. They will take Atherton Drive to Woodward Avenue where they will travel to Moffat where they will turn right. At Austin Road traffic headed to southbound Highway 99 will go straight. Motorists needing to head north on Highway 99 will turn left on Austin to reach the onramp on the east side of the bridge crossing.
Getting drivers to stop waiting for the last second to merge is the key to reducing accidents that are six times more likely to happen on the 120 Bypass than on a typical stretch of California freeway based on a Caltrans survey.
Preventing the last second merge also will help improve traffic flow. Currently such maneuvers force the right lane to slow down and often come to a stop so a merging vehicle can get in at the last second. That creates a “slinky” stop and go during the afternoon commute backing up eastbound traffic up as far as the Airport Way interchange.
Caltrans is moving forward with the first phase of a $131.5 million project at the 120 Bypass and Highway 99 to improve vehicle movements and capacity. The project, expected to break ground next year, won’t be in place until 2024.
In the meantime Caltrans is taking steps aimed at reducing the potential for carnage until two lanes are in place for eastbound 120 Bypass heading toward Modesto.
Caltrans has already placed temporary lane delineators and route shields on the pavement for eastbound 120 Bypass traffic as it approaches the Highway 99 interchange. Based on calls there is an accident every 15 hours at the interchange and freeway approaches in a typical year that requires Manteca Fire Department units to respond.
The Caltrans improvements are aimed at combatting the primary contributing factor to collisions — motorists in the left lane trying at the last moment to merge into the right lane that at peak periods when it is not at a virtual standstill is moving well below the posted speed limit due to congestion.
The shields are designed to remind those that drive the route on a regular basis as well as alert those not familiar with the roadway that a lane split is ahead.
The latest safety measure is the outgrowth of a 120 Bypass safety committee working with Caltrans and the California Highway Patrol that Manteca Councilman Gary Singh serves on.
In 2019 in a bid to improve safety Caltrans installed 2,700 feet of wider, 8-inch, double-white striped lane delineation, from just east of the Main Street overcrossing to the southbound Highway 99 connector ramp, is also to discourage last-minute lane changes. Crossing over double-white stripes is a traffic violation.
Stay In Lane signs were installed on both shoulders, just west of Van Ryn Avenue bridge, to help reduce the frequency of vehicles queue-jumping for southbound Highway 99 and sideswipe collisions. Watch For Stopped Vehicle signs were also installed on both shoulders, just west of the Main Street overcrossing, to help reduce the number of rear-end collisions.
Those improvements were made after Caltrans installed advisory signs on the Airport Way and Union Road overcrossing advising motorists of the upcoming lane splits.
The first phase of the interchange improvements involves:
*widening the eastbound 120 Bypass to southbound 120 Bypass from one to two lanes.
*removing the Austin Road overcrossing and replacing it with a longer span that ultimately would allow eight freeway lanes plus auxiliary lanes on Highway 99. The replacement bridge would span the Union Pacific Railroad tracks as well eliminating the at-grade crossing on Austin Road.
*adding a new connector road Austin Road to East Woodward Avenue. The existing railroad crossing on East Woodard Avenue would be modified to conform with the new connector road and provide access to Moffat Boulevard.
*modifying the existing northbound Austin Road exit ramp to conform to the higher overcrossing profile of the replacement bridge.
*closing the northbound onramp and the southbound off-ramp for Highway 99 at Austin Road. The length of the closure is currently estimated at 9 years. Reopening of the replacement ramps will depend on the availability of funding for the third phase.
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