SMART will be a net negative on greenhouse gas emissions

The SMART train, now under construction, was marketed to voters as a climate change solution, and a rough analysis of the initial operating segment seems to substantiate that claim. Unfortunately, the advantage evaporates with the inefficient second operating segment to Cloverdale.

Critics have decried everything about SMART, but one of the most pernicious ones that has remained unexamined was the critique of SMART’s fuel efficiency. At only 1.1 miles per gallon of diesel fuel, the cars seem like the height of inefficiency. How could SMART claim its operations would reduce transportation greenhouse gases when it’s so clear it won’t?

SMART’s initial operating segment, from San Rafael to Santa Rosa, will serve 28.5 million weekday passenger miles every year and travel about 332,000 miles doing it.* At 1.1 gallons of diesel per mile, that means it will get about 42.8 passenger miles per gallon (pmpg). Since diesel emits more CO2 per gallon than gasoline, we’ll need to revise it down to the equivalent of 37.4 passenger miles per gallon (pmpg-e), roughly the same as a hybrid. Not bad.

According to MTC, cars’ fuel efficiency will get up to 32.2 mpg over the next 20 years. But this is the sticker value. Realistically, cars get about 13 percent less mileage than that (according to Consumer Reports), and in stop-and-go traffic it can be cut down another 40%. With 1.2 passengers per mile, that adds out to 26.9 pmpg during commute hours.

In other words, SMART will very likely emit fewer greenhouse gases than the cars its trips will replace, at least for the initial operating segment (IOS). The full line, however, won’t be quite so great.

The IOS is actually the most efficient part of the SMART line, at least according to official ridership figures. Adding extensions to Cloverdale and Larkspur will lower the train’s efficiency by quite a bit, to 26.3 pmpg-e. This is only as good as a car. We can cross off the full system for greenhouse gas emission reductions, at least if CAFE standards have anything to say about it.

Had SMART not been so financially constrained, it might have pursued electrification from the beginning, a $70 million investment that would have provided cleaner (and faster) service to the corridor.

This is not an indictment of the SMART system. It does not measure how the system will encourage people to swap car trips for walking trips, which happens when people use transit. It also does not take into account the annual mobility benefits for users, which will likely be worth hundreds of millions of dollars per year.

Indeed, individual transit lines are not meant to be climate change solutions on their own. They are like fax machines, enhanced by and enhancing other lines nearby. The accrued benefit of the network, as a whole, is enough to change how people live and travel. And that is what the SMART effort is about: not a final solution to our carbon footprint, but another link in the chain.

*People have complained that the Dowling ridership estimate was overoptimistic, and was not “accepted” by the SMART Board. Given that the latest numbers are used in financial planning and therefore underpin much of the financial structure of the system, I’m more confident in them than speculation from critics. However, if you wish to reduce ridership by some percentage, the precise weekday passenger miles estimate is 28,457,926 per year, assuming 265 working days.

About David Edmondson
A native Marinite working in Washington, DC, I am fascinated by how one might apply smart-growth and urbanist thinking to the low-density towns of my home.

13 Responses to SMART will be a net negative on greenhouse gas emissions

  1. Franz Listen says:


    Isn’t 28.5 million annual passenger miles divided by 332,000 miles, something closer to 85 pmpg ? I know that there’s a slight adjustment for the 1.1 gallons, but with that I still get 78 pmpg. Did you divide everything by 2? If so, I think that you might have cut the effectiveness of the Ghg savings for SMART in half.

    • Oops. I neglected to multiply the vehicle miles by two to reflect the fact that these are two-car trains.

      • Richard Hall says:

        Dave – suggest the following changes.

        1. You take the train’s sticker mpg at face value, but yet you discount car’s mpg. It would be only fair to decrease the train’s mpg by 20% from advertised (ideally you should discount by the same amount as the car).

        2. Cars carry 1.67 passengers on average, 1.13 during commutes.

        3. Mpg for vehicles in Marin are typically *much* higher than the national average – there are more Priuses and Leafs here than almost anywhere and people drive later model (greener) cars.

        4. You need to consider that at least 30%, more likely 50%, of the trains riders are already transit (bus) riders, you’re not causing them to switch from cars to transit. So you need to halve the mpg (sorry, that cancels out your 2 car train).

        5. You need to add at least 25% “deadhead miles” with trains needing to get from the depot to the point of departure at the designated time. This factor is going to be particularly acute for SMART with a single track most of the line length where it will have to “shuffle” trains at specific passing points.

        6. Your passenger miles figures really need vetting. The Dowling study is preposterous. I used the San Diego Coaster population served as a baseline and then divide by the relative population served by SMART. I make it that the Coaster serves 4x as many potential riders as SMART (Inhabitants of towns along the trainlines). Then reduce by a further 40% as unlike the Coaster SMART does not go directly to a major employment hub. Given this then I make SMART will have (at best) 20.5 riders on average, and most will likely ride only half the 38 mile line length each way each weekday. I make it having about 1.87m passenger miles per year. Your 28.5m figure sounds preposterous. But then so is calling SMART smart.

        Finally whatever result you get you need to then work out the emissions reduction / cost ratio. For instance the Mckinsey abatement curve states that you should be able to reduce 1 metric ton of CO2 at a cost of no more than $50 (otherwise you are wasting money and there is an opportunity cost).

        By my math the SMART train still moves the needle the wrong way. You might achieve much more sizable emissions reductions, and mobility increases by simply buying every ~2 riders a Tesla Model S and letting them carpool.

        • 1. Disagree. Trains are operated by trained professionals and their systems will let them hit their fuel economy standards. Cars are routinely poorly operated. I’m going off Consumer Reports.
          2. I was aiming for commute times, as those are the trips SMART is targetting, hence the low passengers per vehicle, but I’ll accept the lower number.
          3. Disagree that it would matter. These are not just for Marin riders, it’s principally for Sonomans. Maybe add one or two MPG to the car.
          4. Disagree. There aren’t good bus connections between Sonoma and Marin, nor between the stations or city centers. Maybe 10% take bus now, but that’s pure speculation.
          5. Maybe, but I’ll say that, with parking lot heat islands, it works out.
          6. Disagree, for all the reasons I mentioned.
          7. The purpose of the train is to provide mobility, not to be the climate solution. Adding more cars to the mix runs counter to that aim, so, no, buying people Teslas won’t do for all the reasons I mentioned in my piece on Operation New Leaf.

          Think whatever you like. I wanted to investigate how this could work with the best assumptions I could figure, and it ended up being a wash, justifying both positions, depending on the train you examine. And there is space for you to fill in your own numbers, too.

          • Richard Hall says:

            So now mobility is now the stated aim? The logic behind SMART seems to be an ever moving target. I can’t keep up. It was clearly sold to voter as reducing congestion and greenhouse gases (not to mention the full line length) and achieves none of these stated goals. So this is yet another bait and switch! What are we to believe next – that SMART will solve world peace? There’s just no credibility left. What do you take people for?

            I don’t see “mobility” defined, quantified or better yet effectively considered against the many alternatives that might achieve this end for a great deal less money. Not least a system of hybrid express buses that might either use HOV lanes or the “tarmaced” over SMART tracks. Or subsidized zipcars (or equivalent) where we insist these must be Nissan Leafs or Priuses.

            It will be interesting for both of us to see who is right on ridership. Your hopes seem to rest on the miraculous occurring and a study agreed on by no one, not even SMART’s board. The religion just has to end and common sense has to start somewhere.

            The statement about finances being based on the ridership study is more of a signal that the financials are even worse than anticipated than justification. I’d rather place my bets based on similar systems actual ridership and accounting for the significance of the locations served.

            You dismiss deadhead miles – yet this is significant especially for single track SMART. If you want to bring in heat islands then lets throw in the massive amount of emissions generated by the construction of the train and the lines, stations, platforms… all that heavy construction equipment and manufacturing and transportation of your train from Japan, ahem I mean “final assembly” by a Japanese company in Illinois (?) easily trumps your “heat islands” (considering the tiny reduction in car parking SMART will achieve – but won’t those cars simply park at new car parks at stations in Sonoma now instead?)

            But you knew we’d agree to disagree. Now SMART’s been voted through on three near proven falsehoods (reducing congestion, emissions, track length) the hunt for new justification seems to be on. I think most folks can see through what’s happened here.

          • Dead-head might be worth another trip or two per day, but single-tracking doesn’t change a thing about that. The system is designed to allow trains to move at full speed in both directions.

            I bring up the financials because there’s a myth that because the Dowling numbers were never “accepted” by the Board that they’re suspect. They never had to be accepted by the Board in any official capacity when they were presented, but the fact that the Board accepts figures derived from the ridership is tantamount to acceptance of the ridership.

            And a) I’m in no official capacity to make claims from SMART, so I’m not sure how I can change SMART’s stated aim; and b) I still think that SMART will reduce CO2 emissions, that it will build the full system, and that it will help reduce traffic congestion.

            As I said, feel free to interpret these numbers how you like. You may think you were duped. I don’t think you’re right about that.

          • Richard Hall says:

            I also need to add that I must give you credit Dave. You will actually go toe to toe on a conversation about the facts, with facts and references. This generates a far more productive conversation and I think readers can take more away from our rabid disagreement and be better judges themselves.

            I continue to be astonished by groups and individuals who do not keep up with the facts and hold a reasonable conversation. These are the “shoot the messenger” and “they’re spreading disinformation” angles from groups (with initials SSR and their representative JFG) that repeatedly fail to produce any facts or specifics. They produce so-called fact sheets devoid of facts and filled with statements that may be based on what they believe to be common sense.

            So between my vociferous exchanges I did want to convey my respect.

            And BTW regarding Downling, suggesting that they were simply “not accepted” is a gross distortion. All the major agenicies said they are incorrect. To cite sources I’ll just restate what’s a matter of record from TAM:

            “Commissioner [and Marin Supervisor] Arnold noted that although the updated ridership projections don’t seem to match original projections, a joint review of the Dowling report between SMART, MTC and Dowling resulted in agreement that the numbers were incorrect.”

            Source – TAM, page 7, 3rd paragraph from the bottom:

          • Thanks, I appreciate it.

            We’ve discussed that specific paragraph before, I believe in a Patch comments thread. I pointed out there, and will again here, that you misquote it. It reads:

            “Commissioner Arnold noted that although the updated ridership projections don’t seem to match original projections, a joint review of the Dowling report between SMART, MTC and Dowling resulted in agreement that the earlier numbers were incorrect – she also indicated that the current estimates were revised down by SMART to ensure a conservative projection.” [emphasis mine]

            You omitted the bolded “earlier”, which shows there was agreement that the original numbers were wrong, which led to the second ridership estimate that I am using here and which are referred to as the “current estimates” under discussion in that meeting.

      • Franz Listen says:


        If a 2 car train goes 1.1 miles on a gallon of diesel, then you can just use train miles, not vehicle miles. Multiply the number of train schedules by the length of the line. This is critical, since otherwise you’re undercounting the benefit by half !


        Trains need not have anything close to a 25% deadhead. Once they leave their base, they can be in service.

        Your point #3 has some validity, but agree with Dave that it would be a small adjustment

        Point #4 raises an interesting question. If there were no SMART, then some people who ride SMART would be on the bus. OK. Now, what if there were no bus? A large number of the transit dependent population who ride it would not be making trips at all. So if we do a GHG analysis for buses (by your logic) we need to compare it – not to cars – but to a baseline in which most of the trips wouldn’t exist. By that standard, we’d find that buses may provide some mobility, but move us in the wrong direction from an emission standpoint.

        • Richard Hall says:

          Actually point #4 becomes worse than that. SMART is diverting transportation funding that could have been invested much more effectively in hybrid buses achieving 5mpg. So in fact what’s not measured at all here is the opportunity cost of SMART – what if we had invested that $590m, ahem, I mean $1.1bn+ after bond interest in express buses. We could have had a fleet of luxury buses serving all corners of Marin. We could have subsidized the fares. We could have generated many, many more riders.

          Hybrid buses get 5mpg and with 10 passengers on them that equates to 50mpg per passenger. It’s going to be hard for SMART to compete with buses that can pick up from many more points and get people directly to employment centers like SF and Oakland without connecting like SMART.

          SMART by comparison with it’s paltry 20 riders @ 1.1mpg (taken as gospel, when nearly all other train promises have been broken) gets 22.55mpg per passenger. Again, if you think the average number of riders is much higher I’m not seeing the evidence. And bringing up Dowling figures as credible is flogging a dead horse.

          A 2031 car (midpoint) gets 57mpg, with 1.13 passengers (which I deem unfairly harsh) and a 20% discount for advertising you get 45.5mpg per passenger. This again ignores that Marin drivers drive cleaner, newer cars than most.

  2. Mike says:

    Dave, get yourself a copy of the Dowling study and look at the numbers.

    According to Dowling’s ridership study

    In 2015, during the AM Peak hours

    1) Only 34 riders will take trips within Sonoma County
    2) More riders will take trains northbound out of Marin than take trains southbound
    3) More riders will get on trains in San Rafael traveling northbound than get off trains traveling southbound

    (Note: the reverse happens in the PM peak hours)

    In 2035, during the AM peak hours

    1) Only 82 riders will take trips within Sonoma County
    2) More riders will take trains northbound out of Marin than take trains southbound
    3) More riders will get on trains in San Rafael traveling northbound than get off trains traveling southbound

    The reverse happens in the PM peak hours.

    These are obviously stupid projections. As I testified at the SMART board when they were released, “even I know they’ll be more than 82 riders in Sonoma County.” No one believes that the trains will have more passengers leaving Marin in the AM than coming into Marin. No one. Not Judy. Not Diane. Not Al. No one.

    Watch the discussion at the July 2011 TAM Board meeting when this was discussed
    at the meeting OR the Diane Steinhauser’s presentation to the Novato City Council
    preceding the TAM meeting. Both are on video. There was widespread disbelief that the study was being used to justify anything.

    Bottom line: No one believed the numbers, because they didn’t make any sense. Dowling’s reputation was significantly burned, particularly in Sonoma County, which couldn’t believe
    he’d go public with such a stupid projections. And in a meeting at the MTC which i participated in, he admitted the projections needed to be revised. (They never were.)

    So, please, stop referring to them. It’s a waste of time.

    Note: SMART will have to update its ridership analysis in order to complete the EIS and apply for the “Small Starts” funding. That ridership analysis will be required to use “benchmarked” models (akin to the ones used in the 2006 ridership study) and are likely to show lower ridership than the 2006 study (prorated to half the line) because population growth is lower and projected to be lower than was assumed in 2006 and because it will be the first study that is applicable to the IOS.

    That EIS should also have updated figures on CO2 emissions and be required to account for the numbers of rail passengers that are coming from other transit.

    It should also contain an updated financial plan — one that hasn’t been updated since Feb 2011. Wonder why? Farhad is doing an excellent job keeping the Board and the public in the dark about SMART’s precarious financial position once it starts operating the trains. And the Board doesn’t seem interested in whether they’ll be able to afford operating the trains once they are up and running. If they did, they would evaluate financial impacts prior to authorizing any expansions.

    Once the trains start to operate is when SMART’s financial position will take a turn. Without passing an additional 1/4 cent tax, once the next recession hits, SMART’s finances will be highly dependent on sales tax revenue growth. This means once the next recession hits (and it will hit probably twice before the sales tax comes up for renewal), SMART will be faced with significant service cuts in order to balance its budget. (e.g., eliminate weekend service.)

    Trains are expensive to operate. The public was sold a bill of goods. It will become apparent once the trains begin to operate and generates few benefits because then we will be able to count (rather than project) ridership.

    • Richard Hall says:

      Mike – I read from Measure Q “Sonoma-Marin Area Rail Transit District be authorized to provide …. with an annual spending cap, independent audits/oversight”.

      What is the annual spending cap? Will this be hit if ridership is low and they have to top up operational costs.

      Are the independent audits/oversight happening? This appears to be an obligation. There are already significant enough concerns, and a lack of financial transparency, or defensible ridership numbers to be demanding this occur. Who do we go to to demand audits, the financial plan? This train needs to be put back on the original rails. Seems like every promise made is broken. It’s irresponsible for taxpayers or the feds to pump more money into this thing without these safeguards.

      Whose guarding the hen house? (Oh that’s right, the foxes).

      • Mike says:

        There are financial audits performed and available on SMART’s website. These audits, however, are only of current expenditures and accounting. They are not audits of financial plans, because there aren’t any new financial plans. Also, auditors don’t audit “financial plans.” The oversight of SMART’s financial plan is supposed to be performed by the Board. As it has incurred no political pressure to do so, it has apparently ducked this responsibility. (My guess is that if you ask, they’ll say “they’re working on it as part of the NEPA EIS requirements.”)

        There was to be oversight provided of a “citizens committee,” the Citizens Oversight Committee. The last time it met was June 2012. (Minutes are on the Board’s webpage.) Minutes of those meetings aren’t available until the agenda for the subsequent meeting is public. As a result, the public may not review minutes for very long time periods. There are no videos of those meetings. I don’t know whether audio recordings are made.

        I have not been aware of any COC member complaining about the reduced role they are currently playing. They were meeting regularly in early 2011. It came to an end when Farhad fired David Heath.

        I have never looked into the “spending cap” issue and how it is administered.

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