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Manteca finds way to move four PG&E poles for $4 million
Union interchange

The popularity of the Sizzler restaurant could help cover the city’s share of relocating four PG&E transmission lines that are impeding the start of construction of the diverging diamond interchange at Union Road and the 120 Bypass.

The four poles will cost upwards of $4 million to relocate. PG&E will cover half of the cost while the city is responsible for the other half. The San Joaquin Council of Governments has agreed to cover 50 percent of the city’s share of the transmission pole relocation up to $1 million from Measure K sales tax receipts

The contract with PG&E to go ahead with the work will be before the City Council when they met Tuesday at 7 p.m. at the Civic Center, 101 W. Center St.

Also on Tuesday’s agenda is a contract to exercise BMW Management’s option to buy 27,688 square feet of city land they have been leasing for an expanded parking lot. The sale price is $470,356.

Given the land was purchased with the last redevelopment agency bond that was issued, the $470,356 can be used for any capital projects tied to the issuance of those RDA bonds that includes the Union Road and 120 Bypass interchange.

Caltrans has provided a letter to the city noted since the actual construction of the Union Road interchange project is being funded 100 percent with local funds and involves no money from state or federal sources the state isn’t a part of further right-of-way activities that includes sharing in the cost of the relocation. That had been a sticking point given at one point Caltrans contended PG&E should pick up 100 percent of the cost.

In a memo to the council staff noted they have been working with Teichert — the low bidder for the interchange project — to apply value engineering to potentially reduce construction costs by up to $500,000.

The $28.4 million project being funded from redevelopment bond money, Measure K sales tax, and fees paid by growth is expected to start after July 1.

Why the diverging

diamond design was

selected by Manteca

The diverging diamond approach was recommended by Public Works Department staff after they were tasked by elected leaders to try and come up with the most cost effective upgrade for the interchange.

The only other requirement was to move larger volumes of traffic.

Originally the plans called for a half cloverleaf that would have required taking nearby property including several homes.

Staff looked into diverging diamond designs that were deployed in other states that were selected not for cost savings as much as it was to place interchanges that worked effectively in developed areas without taking more land and to improve safety.

In the case of Manteca the design means a project price tag that was $10 million less as no additional land was needed. Also a cloverleaf style interchange would have required demolition work resulting in a longer construction time frame.

As an added bonus the design allows for faster and smoother traffic flow and — based on observations of diverging diamond interchanges in place — less severe collisions as well as fewer accidents.

Caltrans District 10 has helped clear the way for the design that has been deployed in 80 plus other locations in the country — with the nearest being on Mona Lane in Reno

With a diverging diamond interchange the flow across the freeway has lanes crossings to the opposite side of Union Road where the ramps are and then crossing back over at the ramps on the other side of the bridge.

Where the traffic crisscrosses there are traffic signals. On a traditional overpass turn movements on and off the freeway would also go through the traffic signals. That’s not the case with a diverging diamond interchange.

If Union Road was improved to a partial cloverleaf interchange as was originally envisioned there would be 24 conflict points for vehicles. The diverging diamond has 12.

Even more significant is the reduction in the potential for frequent T-Bone crashes that can result in extensive property damage and serious injury. There are 20 such conflicts on a traditional interchange and just two on a diverging diamond. Those two would be where the north and south lanes on Union Road crisscross.

Due to the interchange’s geometry the average speed is slowed from 40 mph to 25 mph.


To contact Dennis Wyatt, email