Guest Commentary: Caltrans’ Own Charts Show Expanded Transit More Effective than Road Widening to Speed Travel

Caltrans’ own data: Average speed difference trivial if toll lanes added, HOV lanes don’t encourage carpooling, and transit is 15x more cost effective for speeding travel.

By Alan Hirsch, Yolo Mobility 

If you read deeply and critically into Caltrans documents, you will often find a number of things acknowledged—inconvenient truth not always shared with elected officials.

City and County elected officials rely on agency staff to give honest and complete presentation of objective findings.  However, the reality is elected officials are very vulnerable if an agency’s staff is committed to pursue a pre-ordained solution. Staff can bend their analysis or make strategic omissions of information in their presentation. These are rarely caught by elected officials who don’t have time to read, much less understand the reports.

Then it’s up to a rare whistleblower and or nerdy gadflies to protect the public interest by catching this, and making public comments to electeds who otherwise don’t have time to read everything.

But in the end, it’s up to courageous electeds who are willing to both listen to the outsiders, and are then open to changing their minds, if the agency solution is to be questioned if its pre-ordained solution is in the public good.

This manipulation of data does come from all government agencies, or even most, but this Machiavellian approach to public policy can hard backed into the culture of some.

Dance between Caltrans and Local Electeds

A dance of credibility and accountability is now begun between Caltrans and the local city council members who sit on Yolo Transportation District Board.

Just two weeks ago a whistleblower at Caltrans, a hi-level Deputy Director of Planning at Caltrans, resigned, stating Caltrans’ methods to advance Yolo I-80 violated environmental laws.  This fit into a bigger picture of concern about Caltrans’ veracity: a UC Davis study has shown Caltrans consistently overstates the benefit of freeway widening to elected officials by understating Induce Traffic Demand. And thirdly, UCD Professor Susan Handy, head of the National Center for Sustainable Transportation, has written a letter stating the Caltrans Widening plan not only won’t fix congestion, but will hurt transit ridership and the environment.

Adding to this now is a fourth finding: in a close reading a hidden Caltrans report on alternatives to improve travel on the full I-80 corridor show how upgrading the Capitol Corridor rail service to 100 mph is 15 times more cost effective than road widening.

The public should watch to see if electeds on the 5-member YoloTD board, including Davis’s Josh Chapman and Lucas Frerichs, have the courage to revise their positions taken based on Caltrans information.

What Caltrans Own Numbers Show

The three data tables below are from the larger Caltrans I-80 Comprehensive Multimodal Corridor Plan (I-80 CMCP). It considered five alternatives to improve mobility for the entire I-80 corridor-from the Carquinez Bridge into Sacramento. The plan ranked the alternatives based on travel impact—including one that upgrading the neglected Capitol Corridor rail service to 100 mph. Others encouraging more carpooling via adding HOV carpool lane or adding managed toll lanes—aka HOT or “express lane” (a Caltrans marketing euphemism).  There was also TDM option: Transportation Demand Management strategy of mostly supporting shift to carpooling, or promotion of fixed routed or shuttle or micro transit bus without unimproved infrastructure.

It’s also worth noting Caltrans did not study a regional (3 or 4 county) bus rapid transit (BRT) option to use freeway express lanes as another transit alternative: interregional/intercounty bus travel in the “capitol corridor falls between the cracks of county bus services, or possibly because Caltrans does not want competition for it rail service.”

Still, the flawed study does give a perspective comparing freeway widening with 100 mph passenger rail service—even with only 4 or 5 stations along I-80 corridor.

Caltrans in their I-80 CMCP then estimated the travel speed difference for the average traveler for each of the “scenarios,” along with it costs and benefits, generating a benefit/cost ratio.

To cut to the chase:  the Capitol Corridor upgrade option is 15x more cost effective.  And that the average speed improvement for drivers is only around 2-4 mph even for most extensive road widening proposal. And vehicle hours traveled difference between them all is also just few percent different even with maximum road widening.  The un-peer-reviewed report also seems to once again underestimate the induced traffic compared to what independent academic studies, so the numbers in these table are likely to overestimate the benefit of wider freeways, meaning the 100-mph rail alternative might likely be ever more advantageous.

Report Hidden from Electeds when deciding on I-80 Alternatives

Conveniently for the advocates of road widening at Caltrans on I-80 Yolo widening, these results were not released until after EIR alternatives for Yolo I-80 widening were chosen by electeds.  While the report was finalized in January of 2023, it was not released to the public in final form on Caltrans’ website until May of 2023. This is long after YoloTD electeds and Caltrans agree to EIR alternatives in early October of 2022 by signing the YoloTD/Caltrans MOU document.

The CMCP has never been presented to YoloTD Board. Supervisor Lucas Frerichs did ask one question about it at the board’s September 2023 meeting, though he  did not follow up to ask about the contents.

Below screen shots are pages from Caltrans’ full I-80 CMCP multimodal corridor study, finalized  1/26/2023 but not made public until May 2023—long after I-80 EIR alternatives were considered, and meaningful transit options rejected.


Rail upgrade to 100 mph 15x more cost effective than freeway widening: Caltrans Table 5.13
Source: Caltrans I-80 CMCP Page 103

Note bottom line in chart: CC cap corridor scenario 4 is 3.05 vs 0.22 for best road widening option scenario 3. HOT (Tool/HOV lanes)

This chart raises questions as to why full corridor rail transit alternative (not just buses in the short segment within Yolo County) were not included in Yolo80 EIR  study, particularly because 95% of traffic on the Yolo Causeway begins or ends in Solano County and points west.  In the below chart Segment 6 is Davis and segment 7 is Causeway, but of course the rail upgrade (Scenario 4 CC) needs to be analyzed for entire corridor (last line of table).

New carpool lanes do not make freeway use more efficient. Caltrans Table 5.3
Source: Caltrans  CMCP page 95

Chart shows less than 1-4 % increase in carpooling if HOV lanes are added shift from (1.32-to max 1.37 people in the average car).  This is change in average vehicle occupancy between current “no build” vs scenario 2 & 3 HOV and HOT scenarios). This mean the user of carpool lanes are not due to a behavior change: they are “dates” or family or groups who were going to travel together regardless of the existence of the lane. This mean HOV lanes have not environmental advantage, they just add lane capacity to the freeway.  Note also that “Carpool only” is in practicality just a theory: With tinted window and enforcement minimal one can believe this is just Caltrans justifying on paper building another lane- maybe to prevent shift of money to a local transit agency.  On highway 99 in Sacramento it was found 48% of carpool lane users were single occupancy vehicles- so they become as congested as the other lanes: there is no reliable automated way to enforce HOV lane usage.

Only 2-4 mph faster travel if widening nearly the full length of I-80—i.e., only 2- to 4-minute average travel time decrease with Express/HOT/HOV managed lanes: Table 5.9

Source: Caltrans CMCP page 97.

Note: Data in this table should be accept know this is Caltrans “best shot” to show the freeway widening—which is already begun—was the right thing to do.

Then begin do a critical analysis Caltrans’ record of overstating benefits of freeway widening by understand induced traffic effect.  According to UC Davis ITS study, Caltrans historically has chronically understated induced demand from freeway widening. The small VMT increase in this chart due to adding many miles of HOT/HOV lanes seems highly suspect. The induced demand for the Yolo80 project predicted by the UC Davis induced demand calculator for just that 17-mile segment is about 450,000 vehicle miles per day. Caltrans’ induced demand estimate for adding at least twice as many lane miles in CMCP study is 400,000 miles (no build vs both HOT/HOV). The UC Davis model is not controversial: it is accepted by Caltrans as accurate within 20% .

Recall also that the Caltrans CMCP is not formally peer reviewed and is not subject to legal challenge so there is no outside quality control of it modeling.

The table also gives the VHD: Vehicle Hours of delay. Note the small difference in delay between  managed lanes compared to the rail alternative: less than 3%. The difference in VHD Hours between no build and HOT2+ is 14,000 hours. This sounds like a large difference, but it is less than a 6% increase in average travel time.

Caltrans typically pushes the “absolute” number (e.g., 14,000 hours here), but it’s more useful to normalize this to a 6% increase for the average drive time and then weight this tradeoff for against the sprawl and climate change impact of the extra freeway lane. Again, this CMCP is not a peer reviewed document, but reflect Caltrans “best shot”—likely to justify widening it already started.  So, it does not surprise that if resulting induced demand was understated for build options (1,2 & 3), VHD, VHT and VMT are likely understated relative to rail (CC) and TDM options. Thus, the benefits of HOT/HOV alternatives are likely overstated—meaning rail might be even a better investment.

Will YoloTD act to turn from advocacy to stewards of the public trust?

A substantial among to data questioning has surfaced about the road widening and transit option, and Caltrans method.

We will now see if  YoloTD board and staff have the courage to be more critical Caltrans data. Best practices would be for the board to hire an independent traffic expert—one not dependent on Caltrans for future work—to review Caltrans DEIR and CMCP before it is released. They should not depend on privately-funded environmental lawsuits to once again exposure Caltrans’ questionable methods.

The public should also ask of the  YoloTD board: Why have you already lawyered up?  Is this to defend Caltrans against private environmental law from group like ECOS does, that has time and again have forced locals to confront the inconvenient truth of Caltrans and invest in transit, or are these taxpayer-paid lawyers to protect the public interest in Yolo County from Caltrans’ questionable methods?

About The Author

Disclaimer: the views expressed by guest writers are strictly those of the author and may not reflect the views of the Vanguard, its editor, or its editorial board.

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  1. Walter Shwe

    Expanding mass transit is a public financial boondoggle. Republicans want to completely kill Amtrak. The vast majority of people have voted with their vehicles on this issue. They don’t want to be subjected to the constraints of mass transit time schedules and routes. I am not just talking about trains, but buses too. Regurgitation of this issue won’t change the facts regarding its unpopularity.

      1. Walter Shwe

        I guess you would rather spend vast amounts of funds on transportation systems that relatively few will actually use. Americans by overwhelming margins have decided to drive their own vehicles or fly instead of utilizing alternatives such as Amtrak, BART and light rail. In other words it’s not even close. 

      1. Keith Olsen

        It wasn’t Republicans that pushed for the Bullet Train to Nowhere.  It’s been a total disaster and waste of near $100 billion.

        And how haven’t the Republicans abided by the vote?  What are you even talking about?  It’s still getting at least somewhat built.

          1. David Greenwald

            Not really. A reasonable alternative to freeway expansion would have been a connection of BART to Sacramento Light Rail. You raised the bullet train as a red herring. There’s a difference and you know it.

      1. Walter Shwe

        Then you and other Republicans really don’t respect the will of voters. Republicans are rigging elections so they always come out in their favor. In 2020 Republicans were caught doing just that in multiple states.

        1. Keith Olsen

          What are you talking about?  The Bullet Train to Nowhere already won approval in an election.  How does rigging have anything to do with it?  But if you took a poll most voters no longer approve of the Bullet Train.

  2. Richard McCann

    What we really need to know to assess the alternatives is an understanding of the purposes of the trips being made across the I-80 corridor on the stretch from Fairfield to Sacramento. I understand that the worst commute traffic is actually eastbound from Sacramento to Davis, not the other way around. (Possibly created by the lack of housing for the missing middle market that serves employees of many businesses in Davis.) As for west bound, we’re all familiar with the Thursday/Friday afternoon backup that appears to be created by Tahoe traffic. But these observations are really anecdotal. We need to know more detail about these situations so we can target the appropriate solutions. Transit is a viable solution for those who make frequent repeated trips on the same route and can understand the system quickly and easily. It is not viable for tourism (except in dense cities) or infrequent long trips to recreation areas.

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