An innocent reader interested in learning about transit oriented development projects would have learned from official county and city sources that one of the major justifications was to reduce greenhouse gas emissions and fight climate change. Here is a selection of the justifications made to justify a number of projects in Marin:
– The County of Marin told us in official documents that Priority Development Areas would “lower greenhouse gas (GHG) emissions”
– The Larkspur Station Area plan public workshop presentation told us that we should add 920 units of high density housing in order to “minimize greenhouse gas emissions”
But what if none of this turned out to be true? What if all of these projects actually increased emissions? What if the claims that “if we don’t build high density here then we’d increase emissions by building sprawl elsewhere?” rang hollow? Then shouldn’t we re-evaluate all those projects based on the new information? After all the United Nations Intergovernmental Panel on Climate Change (IPCC) stated unambiguously that the climate change crisis has become so significant that we can’t continue with business as usual.
The Changing Landscape: Car Emissions Have Dropped
Many of us still feel a modicum of guilty pleasure driving a vehicle – based on information such as the above we presume that while taking transit can be inconvenient, we’re doing our bit to save the planet because transit has lower emissions. But the reality is that cars have come a long way in the last few years. Market pressures have led to cars making immense improvements in fuel economy and this almost directly results in lower emissions. In 2012 the average new US car achieved 23.8 mpg (source: EPA) a 1.4 mpg improvement in just one year.
It’s important to understand that miles per gallon figures are directly linked to emissions. If you burn 1 gallon of gasoline in an internal combustion engine you will emit, on average, 8,887g of CO2 according to the EPA. Diesel emits slightly more per gallon – 10,180g CO2.
The California Air Resources Board’s EMFAC database provides the official emissions figures used by transit agencies, cities and counties. Marin has commissioned consultants ICF International who inform me they use this data with their own proprietary model as they revise Marin’s Climate Action Plan. This EMFAC data uses actual DMV data regarding the specific vehicle fleet – down to the make, model and age – registered to be on the road in any selected county. It then applies official forecasts based on improvements from Pavley legislation and California’s Low Carbon Fuel Standard (LCFS) to project emissions for cars and transit out until the year 2035.
However the EMFAC database has yet to consider in its projections the much more aggressive Pavley II legislation enacted into law by the EPA in August 2012. This enacted legislation states that the average new car must achieve 54.5 mpg by the year 2025. Sources in the ARB report that they are confidently on track to meet this target.
Since this more aggressive, enacted legislation is not considered we must treat any car emissions projections over-estimates (actual emissions will be lower).
What About Transit?
As previously covered in Planning for Reality, transit emissions historically have remained fairly static over the past 20 years. The California Air Resources Board EMFAC database also provides insight into emissions per vehicle mile for buses. More importantly it provides this data specific to buses currently used in Marin – and projects bus emissions out into the future.
We know the emissions for the SMART train as SMART published this in their SMART vehicle study. SMART locomotives will emit 6,825g CO2 per vehicle mile.
The All Important Passenger Miles Per Gallon
More important than emissions per vehicle mile is emissions per passenger mile. We all know that a bus with 4 people on it will emit far more than the same 4 people in a large SUV because the bus has a larger engine pulling more weight. What’s important is measuring the CO2 emissions generated by transporting each passenger 1 mile.
To arrive at these vital figures requires an understanding of average ridership:
- Cars: The US Department of Transport conducted a National Travel Trends Survey in 2009. Table 16 on page 33 arrives at the average occupancy for cars of 1.67.
- Golden Gate Transit Buses: The American Public Transportation Association’s 2012 Factbook, Appendix A provides detailed information about vehicle miles travelled and passenger miles. Here we see that the system achieved 82,418 million passenger miles and 6,147 vehicle miles – this translates to an average ridership of 13.4 passengers.
- Golden Gate Ferry: The same fact book shows that the ferry system achieved 22,541 million passenger miles and 194 million vehicle miles – translating to an average ridership of 116.5 passengers.
- The SMART Train: SMART does not have official ridership numbers, MTC, SMART and projection authors Dowling all stated in TAM meeting notes that projections are “incorrect”. Reverting to the national figures for trains, bouyed up by rail systems in the northeast with dense monocentric employment centers such as Manhattan and Boston, we can use the same approach above to arrive at an average ridership for commuter rail of 44.1 passengers. This figure is especially generous for SMART that is running in a suburban and rural area and not connecting to major employment centers.Looking at the Altamont Commuter Express (ACE) commuter train in the East Bay which serves a much larger population than SMART in San Jose, Pleasanton and Fremont, the APTA 2012 figures show an lower average ridership of 40.6 passengers. Had this been used SMART’s emissions would be higher on the chart. In the author’s opinion, given that SMART does not connect to major employment centers directly like ACE, and serves a much reduced population catchment, SMART’s true average ridership will be significantly below 40 passengers.
This graph shows the results:
- Cars have lower emissions per passenger mile than the bus throughout the forecast
(Diesel cars, not shown, have even lower emissions).
- While the SMART train has a slight edge until about 2023, just 7 years into operation (when ridership will be lower), for the remaining 23 years of operation cars have lower emissions than the train.
- Golden Gate ferries are not shown on the chart as they have the highest of all emissions at 727g CO2 per passenger mile
But What If…
One question I hear is that if we add more high density transit oriented development then surely we can fill buses so there are more occupants. In reality as buses reach capacity more need to be added – how long would you tolerate waiting for a bus every day when half the time it arrived was full and you had to catch the next one? After wasting 15 minutes a day several times a week you’d change your travel mode.
The most popular arterial routes are already served, adding additional bus service will cause bus emissions per passenger mile to further increase, widening the gap against lower emission cars.
Another objection is that if we don’t build high density near transit here in Larkspur, Strawberry, Santa Rosa, then it will lead to more single family homes with cars which will increase emissions. But given the new data it would appear that such a displacement would likely reduce emissions. More evidence is emerging that single family homes can reduce emissions by becoming more self-sufficient using solar power.
Trains Cannibalize Other More Cost-Efficient Transit Projects
Another objection is that since Marin and Sonoma voted to allow the SMART train to be built, and it will be operating in any case, we might as well fill it as full as we possibly can. After all we’ve paid for the train, it’s free.
[update 4/16 9:15am] However I am now learning that such thinking ignores the reality, which is rail projects cause transit agencies to “eat their young”. This deserves a longer article to explain, but there is fairly clear proof that rail projects such as SMART displace money from far more cost-effective bus services or highway improvements. We already know SMART took $20m+ away rom other transportation service via TAM in 2011 to balance it’s budget, and more recently diverted $20m meant for highways, bike and ped in the Greenbrae corridor project.
It appears increasingly likely SMART may be back, cap in hand, asking for more money just to conduct ongoing operations and potentially deliver the full line length that it promised. Additionally the transit network may pivot in Marina and Sonoma to gear into feeder buses to SMART stations – again diverting/absorbing more money away from more cost effective transit projects.
What Does This Mean?
If this week’s United Nations IPCC report is to be adhered to, which advocates the end of business as usual, then it becomes vital that we reassess justification of transit oriented development projects based on this new data.
We need to educate the public of the new reality. We need our politicians to embrace these facts, and we need plans and outreach to reflect the data.
One Last Consideration
I had an especially enjoyable conversation with a fellow climate change opponent this week who suggested the importance of thinking bigger. He pointed to how a mechanic he knew condemned the Toyota Prius as it generated higher lifecycle emissions than equivalent gasoline models. But he highlighted that the Prius was a symbol – a stepping stone on the way to a time when genuinely efficient cars would emerge (which is now happening).
In the same way there may be an argument that in the long term we need to change people’s travel habits as 20+ years out perhaps genuinely efficient transit will arrive with superior (lower) emissions to cars. However that is not the conversation that we are having, and not the marketing we are being sold as we consider the Larkspur Station Area Plan and similar high density projects.
We need to level-set the conversation, and once and for all put an end to the myth that transit is cleaner than cars. If we continue discussions, planning and processes that are not based on facts then we are not going to arrive at the right outcome.
Only with a fact-based foundation to planning we can have a genuine conversation about fighting climate change and preserving, possibly even improving the quality of life for all.