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I-580: Rolling parking lot?
ACE expansion seen as way to beat coming 26 mph crawl
ACE trains could be stopping at the downtown Manteca station by 2025. - photo by HIME ROMERO/The Bulletin

If you think traffic is slow now for Manteca, Lathrop and Ripon commuters making their way to jobs across the Altamont Pass wait until 2040 rolls around.
Experts are projecting traffic volume on Interstate 580 from the San Joaquin County line to Vasco Road in Livermore will increase by 59 percent. That will slow morning peak commute traffic when there isn’t an accident heading into the Tri-Valley from 35 mph to 26 mph. The return trip in the afternoon during peak hours will drop from 49 mph today to 35 mph.
Similar congestion is anticipated on Interstate 205 through Tracy, the 120 Bypass, and Highway 99.
The numbers are contained in the environmental impact report for the proposed ACEfoward project that would extend Altamont Corridor Express (ACE) service to Merced and enhance Stockton to San Jose service. Comments on the ACE environmental report are being accepted through Aug. 31. For the full report and details on how to comment, go to
The projections are based on job and growth projections in Santa Clara, Alameda, San Joaquin, Stanislaus, and Merced counties. ACE used 2015 — when work started on the project — as the base year for population and job growth. In a 10-year period ending in 2025 Santa Clara County was projected to create 140,000 more jobs and add 159,000 residents, Alameda County to create 90,000 jobs and add 155,000 residents, and San Joaquin County to create 27,000 jobs and add 70,000 residents.
The job gain based on percentage will be the highest in Santa Clara and Alameda counties with population growth gains the biggest in San Joaquin County. Overall, the entire Bay Area is expected to see jobs grow 11 percent by 2025 with population growing 9 percent. In the three-county Northern San Joaquin Valley region, jobs will grow 14 percent during the same time frame and population 17 percent.
The study notes 14 percent of all people in the Northern San Joaquin Valley who have jobs commute to the Bay Area. Another 9 percent work in another county besides their own in the Northern San Joaquin Valley that consists of San Joaquin, Stanislaus and Merced counties. That means there is a possibility of someone residing in Turlock that works in Manteca could do most of the commute by train.
Future traffic will set the stage that will make increased lane capacity a futile effort at some point to prevent the I-205 and I-680 corridors from turning into rolling parking lot status with morning commute traffic essentially moving at the legal top speed when children are present in school zones.
ACEfoward would reroute ACE into downtown Tracy as well as initiate service at the existing downtown Manteca station and add stops eventually in Ripon, Modesto, Ceres, Turlock, and Modesto. The existing Lathrop/Manteca station could be shifted to River Islands at Lathrop.
Existing stations — including the downtown Manteca station — will require additional parking.
Work in the San Jose to Tracy corridor would target congestion points requiring double tracking and other improvements. Track over the Altamont would be realigned and sidings extended.
The report calls for the initial extension of ACE service to go initially at least as far as Modesto. The California Legislature, however, in setting aside $400 million in gas tax revenues last month for the extension of ACE down the valley called for it to go to at least Ceres.

Initially two trains
would stop in
downtown  Manteca
With the service extended toward Modesto/Ceres in the mix, the near term ACE plan would have four trains operating each day from Stockton to San Jose both in the morning and afternoon as well as two trains in the morning and afternoon from Modesto to San Jose.
Without the Modesto extension, six trains would operate in each direction between Stockton and San Jose. Currently there are four morning ACE trains and four afternoon ACE trains.
The long-term improvements call for up to 10 daily roundtrips between the Northern San Joaquin Valley and San Jose, a train-to-train connection between the ACE and BART systems and the extension of ACE service to Ceres, Turlock, and Merced.
The EIR notes the current annual ridership of 1,285,200 passengers would increase by 28 percent by 2025 and 70 percent or 2,186,800 by 2040 with no project.
If the project goes forward without extending service to Merced and with no BART connection ridership would increase 157 percent by 2025 and 243 percent or 4,405,100 by 2040. With a BART connection ridership would increase by 230 percent by 2025 and 339 percent or 5,637,500 by 2040.
Extending service to Merced without a BART connection would increase ridership by 255 percent by 2025 and 372 percent or 6,065,900 by 2040. The Merced extension with a BART connection would increase ridership by 334 percent by 2025 and 474 percent or 7,375,500 by2040.
The train-to-train connection with BART is envisioned for Centerville to Union City.
There are 132 track/road intersections involved with the ACE project. There are 19 locations were ACEforward would contribute significantly to local traffic congestion. One of them is Main Street in downtown Manteca.
The overall project carries a $950 million price tag.
Currently 50 percent of the operating and maintenance costs for ACE are covered by fares. The balance comes from transportation sales tax measure in the three counties ACE currently serves.
Talking points the San Joaquin Rail Commission has about ACEforward include:
uIt would reduce greenhouse gas given the Metropolitan Transportation Commission estimates traffic on Interstate 580 through the Altamont Pass will increase 75 percent by 2035.
uACE Forward would promote walkable/bikeable communities and the revitalization of core urban areas. With the exception of Ripon, all proposed ACE stations in the San Joaquin Valley are in areas which have been designated by the state as “disadvantaged communities.”
uCommuters from communities to the east of Manteca along the 120 corridor running up into the foothills would no longer be able to access trains at the Lathrop/Manteca station since it would be relocated to River Islands making the downtown Manteca the closest stop for them.  That would add to parking pressures for the downtown Manteca station.
uThe 58-mile extension to Merced from Lathrop would require double tracking given ACE can’t use Union Pacific tracks as it is one of the most heavily congested freight tracks in California. ACE would use the new track predominately during passenger operating hours. At other times it could move Union Pacific freight.

ACE times to San Jose would decrease
at least 10%
ACEforward will employ next generation higher speed diesel-powered engines. It would allow top train speeds of 110 to 125 mph for a 10 percent reduction in travel time with the goal ultimately to reduce travel time by 20 percent. Keep in mind that at the same time travel times on freeways along the ACE corridor will increase significantly.
That would mean a current ACE trip to San Jose from:
uLathrop/Manteca would go from one hour and 53 minutes to one hour and 40 minutes.
uStockton would go from two hour and 12 minutes to one hour and 59 minutes.
uPleasanton would go from 59 minutes to 52 minutes.
ACE Forward would allow riders boarding in Turlock to reach Merced in 22 minutes, Modesto in 13 minutes, Lathrop/Manteca in 40 minutes, Stockton in 59 minutes, Pleasanton in one hour and 28 minutes, Great America/Levi Stadium in two hours and one minute, and San Jose in two hours and 20 minutes.

To contact Dennis Wyatt email