Part of project to switch to ramp meters through Manteca and Ripon


209 Business Journal file photo
Northbound Highway 99 under Ripon’s Main Street crossing is being lowered as part of an effort to address traffic congestion and safety on the freeway corridor from Modesto to Manteca.

Northbound on- and off-ramps for Main Street in Ripon will be closed for three months starting in May as part of a $24.5 million project to improve freight mobility, traffic flow and enhance safety along the Highway 99 corridor through Manteca, Ripon, and Modesto.

The closure will allow Caltrans to lower northbound Highway 99 under the Main Street overcrossing in Ripon to improve freight mobility and to increase overhead clearance for commercial truck traffic.

It is part of an overall endeavor that — when completed in January of 2019 — will bring ramp metering to on-ramps during heavy traffic times on Highway 99 through Manteca and Ripon as well as parts of Stockton and Modesto. It is being funded through Senate Bill 1 that raised the gas tax to address road maintenance and traffic operational issues on the state’s freeway and highway system.

In recent years traffic has slowed to a crawl during the morning and afternoon commuters on Highway 99 between the 120 Bypass and Modesto. At the same time traffic volume has been increasing north of the 120 Bypass into Stockton due to increases in truck movements as well as vehicles in general.

Ramp meters have already been installed at Lathrop Road and Austin Road in Manteca as well as on French Camp Road and interchanges in Stockton as far north as the Crosstown Freeway during previous road improvement projects.

Six additional interchanges along the Highway 99 corridor will have on-ramp meters installed. They are:

  • Yosemite Avenue to northbound and southbound Highway 99.
  • Jack Tone Road to northbound and southbound Highway 99.
  • Milgeo Avenue and Colony Road in Ripon to northbound Highway 99.
  • Main Street in Ripon to northbound and southbound Highway 99.
  • Hammett Road in Modesto to northbound and southbound Highway 99.
  • Pelandale Avenue in Modesto to northbound Highway 99.

The project also includes the installation of Intelligent Transportation System (ITS) elements such as changeable message signs, closed circuit televisions and fiber-optics, and traffic management and weather information systems. They will all contribute toward easing congestion and improving safety and efficiency for motorists.

New landscaping will be installed along with an improved drainage system.

Work will occur during both the night and during the day. There could be delays of up to 15 minutes. Caltrans indicated no two consecutive ramps will be closed at the same time.

The established detour to reach northbound Highway 99 from Main Street is to take the Frontage Road north, turn right on Acacia Avenue, turn left on Milgeo Avenue and then take the northbound on-ramp at Milgeo Avenue.

Ramp meters are typically a basic traffic signal with red and green lights tied to a controller that regulates the flow of traffic entering freeways based on current conditions. Such systems have proven to be successful in decreasing traffic congestion and increasing safety by breaking up platoons of cars for more efficient operations via vehicle spacing.