Take a drive down Lathrop Road at mid-afternoon and you’ll get a precursor of what is to come on a roadway that is emerging as a key player in the movement of goods while serving existing and emerging neighborhoods.
Here’s a snippet of such a trip taken Thursday from the new interchange at Highway 99 to Interstate 5 nearly five miles away:
uEight semi-trucks were counted. Residents along the corridor say the count kicks up weekdays as some haulers have discovered it is a way to avoid the stop and go in the afternoon on the eastbound 120 Bypass.
uThere are over 50 residential properties in both Manteca and Lathrop that will need to have significant parts of their front yards chopped off to widen Lathrop Road to four lanes. Doing so will bring traffic closer to their front doors.
uThe pavement between Union Road and Airport Way is some of the worst in Manteca as it is riddled with potholes, patchworks of cracks, and wavy asphalt.
uOne truck — which appeared not to be legal under state truck route laws — made a right turn onto Harlan Road from westbound Lathrop Road with its rear right tire going up and over the curb.
uThere are a number of high school students — mostly from Lathrop High but also a fair amount from East Union High — that walk along or cross Lathrop Road.
uSurprisingly, the traffic stayed below the posted 45 mph speed limit except on the stretch encompassing the two railroad bridge crossings where most drivers picked up the pace. As far as the 35 mph zone in Lathrop nearing the freeway, the congestion was enough to keep speeds down.

Two Lathrop Road
residents alarmed
about more and
more truck traffic
It is on Lathrop Road where Adriana Lopez and Mary Meninga reside — Lopez in Lathrop and Meninga in Manteca. They are miles apart but what brings them together is what the future may hold for their neighbors, those who rely on the corridor day in and day out such as Del Webb at Woodbridge residents as well as those that populate other Lathrop and Manteca neighborhoods, students who walk and cross Lathrop Road as well as those that dare bicycle it.
That future is a Lathrop Road that could exist as a legal STAA route. That’s shorthand for the Surface Transportation Assistance Act of 1982. In a nutshell it allows out-of-state trucks longer than what are legal in California to use certain state highways and designated surface streets.
The Federal Highway Administration website notes the dangers of STAA trucks running on routes not designated as such creates the potential for cars in adjoining lanes to be trapped when the trucks are making right-hand turns and truck tires going up and over curbs and possibly making contact with poles and signs. In order to secure such a designation changes on turn radiuses that don’t comply to STAA standards need to be made.
Manteca made such modifications on several intersections to accommodate trucks making right-hand turns to reach distribution centers within Spreckels Park via a STAA route.
While those accommodations would address safety issues related to STAA trucks, Lopez and Meninga — along with several Del Webb residents — are focusing on issues regarding increased truck traffic that is coming down the road.
Those issues center on the roadway ultimately being brought 20 feet closer to the front door of existing homes, noises and emissions standards for residents that they say will exceed Environmental Protection Agency standards based on setback and how it relates to truck noise and air quality issues on the EPA website, bicycle safety along Lathrop Road, pedestrian safety crossing the road, and the strong propensity for more accidents.

CenterPoint could
help bump up truck
traffic on Lathrop Road
They point to Louise Avenue — a parallel arterial street a mile to the south — where in the past eight years at least two trucks have been among the vehicles that have gone through or hit sound walls that serve as backyard fences of a number of homes.  That includes one truck that ended up in a swimming pool.
Lathrop has indicated it intends to pursue a STAA route designation for the segment of Lathrop Road within its jurisdiction after being requested to do so by a firm that deals within the longer STAA trucks to move goods.
Lathrop Road is already a truck route including through Manteca where no weight limits posted.
While Manteca hasn’t made any movement toward a STAA designation for its portion of Lathrop Road, it has approved the development of more than 3.1 million square feet of distribution centers as part of the CenterPoint Business Park north of Lathrop Road along Airport Way.
There is no direct access to Lathrop Road from CenterPoint as planners call for trucks to use Roth Road to reach Interstate 5. However, that ignores basic “physics” based on how water takes the path of least resistance. The adjoining Union Pacific Railroad intermodal facility where truck trailers are transferred to and from flatcars on trains often blocks the Roth Road crossing for extended periods of times. A primary justification for building the two bridges across the separate UP lines was based on the need to have a road not tied up by stopped trains to improve emergency response and enhance traffic flow. Given UP’s plan to increase movements through the intermodal facility by more than 250 percent in the coming years, it increases the likelihood truck traffic from CenterPoint will travel south to Lathrop Road to access I-5 rather than wait five to 15 minutes for a blocked rail crossing.
And while Lathrop Road is a legal truck route in both cities, it isn’t legal for STAA trucks.

Police not trained
to enforce STAA
related truck laws
 One might think local law enforcement — particular traffic officers — are on the lookout for STAA trucks operating on unapproved routes given the possibility they can roll over curbs, and clip signs where the turn radius is too tight. But there’s a catch. Police and deputies aren’t focusing on STAA issues for a reason.
Manteca Police Chief Nick Obligacion noted his officers aren’t trained to tell the difference between STAA trucks and other trucks. As such they would be on shaky ground writing tickets that could up in court. The California Highway Patrol’s commercial enforcement division is the most versed
While many STAA or interstate trucks have sleepers so do some trucks that can legally operate on California truck routes. Other issues deal with length as well as varying allowances for kingpin-to-rear-axle spacing.
Manteca has one approved STAA route. It starts from the Yosemite Avenue interchange at Highway 99 and runs west to Spreckels Avenue where it turns south. It then goes across the railroad tracks and onto Industrial Park Avenue before turning left on South Main Street and connecting with the 120 Bypass.
Over a decade ago the city was caught up in a snafu when the CHP started ticketing STAA trucks going to and from Spreckels Park distribution centers. Even though the STAA law had been in place for 17 years when the city planned for the truck intense use that involves a large chunk of interstate shippers, they failed to design turn radiuses adequately for the STAA trucks or to obtain STAA classification. Once that was addressed all trucks moving to and from Spreckels Park were legal.
Even Caltrans can fail to account for truck movements. The city and Caltrans went back and forth for years on whether the state would allow traffic signals at Vasconcellos Avenue and East Highway 120. When they finally did OK the signals and completed design work they failed to set back the traffic signals far enough to have a legal right turn radius despite the fact one of the businesses on Vascncellos Avenue is a trucking company.
Given CenterPoint’s promise of 3.1 million square feet of distribution center, there is a high probability some of the trucks accessing the business park’s future tenants will be STAA trucks. By not planning for an STAA route the city is subjecting them to ticketing.

Lopez at epicenter of Lathrop’s effort to secure land to widen Lathrop Road
Since the city has no control over Roth Road to Interstate 5 as it is in Lathrop, that leaves Lathrop Road as the only nearby arterial under Manteca’s control where STAA trucks can access a highway of freeway with a STAA designation.
Then there are the property issues of which Lopez is at the epicenter of with Lathrop’s current plans to widen Lathrop Road to four lanes from Harlan Road to the first bridge over the railroad tracks. Lopez is one of several homeowners that the city needs to acquire land from to complete the 106-foot right of way to accommodate inside lanes of 12 feet in width, curb lanes of 14 feet in width well as landscaping between the curb and sidewalk plus a landscaped median
The widening will eliminate on-street parking, require her and others to make right turns into their property by slowing down in the travel lane, and bring the roadway closer to her front door. Lopez said she has been told she will lose the home delivery of mail and that a solution has yet to be worked out on how the garbage will be collected each week given the solid waste truck would have to stop and block a travel lane to collect cans.
Lopez contends the City of Lathrop has been less that forthright dealing with her and neighbors that speak only Spanish in their efforts to secure their land. As for observations that some have made that “she should have seen it coming” given the city put in place the two railroad overpasses within the last 12 years, Lopez said past city leaders put heavy emphasis on the fact the bridges were for better emergency access and traffic flow and never said it was precursor to putting in place a STAA route.
The STAA route designation aside, motorists using Lathrop Road in Manteca concerns the city will create safety issues by not widening Lathrop Road when traffic congestion justifies it.
Lathrop Road could
be a repeat of East
Louise Avenue in Manteca
They point to Louise Avenue east of Main Street where it goes from two lanes down to one and then back to two lanes as the city has refrained from using eminent domain to obtain parts of the residential parcels to widen the street.
The City of Manteca’s policy is to wait until the private sector develops property fronting a road and then requiring the developer to pay for the work as well as dedicate the right-of-way.  That means it could be a number of decades before Lathrop Road is widened to four lanes despite more traffic being sent down it. Spots where Lathrop Road is widened in front of the Calvary Community Church as well as the fire station outside of the Del Webb community provide an idea of how far the encroachment needs to go into the front yards of existing homes.