The Marin County Climate Action Plan 2014 Draft Update raises many questions. Recently I submitted a freedom of information act request to which I received this response (zip file). The Climate Action Plan proposes that Marin can reduce CO2 emissions by making a major push to switch travelers from cars and light trucks (known as light duty vehicles or LDVs) to transit. This is predicated on transit emissions being lower than cars – but if this foundational math isn’t correct the plan falls apart.
Planning for Reality has major questions about this – if the county adds additional transit as proposed then the result is not a reduction in CO2 but more likely an increase for the following reasons:
- Expanding Transit Reduces Average Ridership: The most frequently used peak time arterial routes are already well served by Golden Gate Transit buses and ferries. Expanding transit as proposed by the plan will result in adding more routes at shoulder periods. This will have the effect of reducing ridership, reducing emissions per passenger mile.
- Omitting Consideration of Advances in Car Emissions: The Climate Action Plan does not appear to be sufficiently considering enacted CAFE (54.5mpg by 2025) and Low Carbon Fuels legislation. Planning for Reality believes that in the future – cars will emit less per passenger mile than transit.
The Marin Climate Action Plan 2014 Draft Update was prepared by outside consultants ICF. The county is spending in excess of $100,000 on this engagement (if you know the exact amount please do let Planning for Reality know, it’s surely out there somewhere).
Expanding Transit, Yet Average Ridership Doesn’t Drop
The records request response affirms the error that despite the plan’s push to expand transit services it fails to consider that average ridership/occupancy will drop and consequently emissions per passenger mile will increase. This means that all calculations for transit emissions are incorrect and under-represent transit emissions.
The response states:
ICF did not assume that the average bus passenger load would change in the future. ICF held the average bus occupancy values of 8.57 passengers per bus for all periods and 9.21 passengers per bus for peak periods constant. No documents are provided. According to a representative of Marin Transit (Reebs Pers. Comm.): “We do not have any future projections for bus occupancy, but I don’t believe it will change significantly in the next few years.”
Data Selectively Under-Represents Transit Emissions
While consultants ICF did leverage insight from Marin Transit on incoming new lower emission vehicles it did not appear to use Marin Transit’s stated average ridership of 6.93 (see this email) instead using a much higher average bus occupancy figure of 8.57, and 9.21 for peak. The calculations behind this are not explained by the ICF document (or any other documents provided).
Furthermore the calculations significantly undercount Marin Transit emissions as they conveniently use “revenue miles” instead of “vehicle miles”. This excludes the significant emissions that occur when buses are moved into position before or after running a route.
Transit is Expanded – Only Not in Emissions Calculations
The plan states:
Expand local and regional bus service in range and/or frequency where service expansion
would result in higher bus occupancy and would result in lower GHG emissions per passenger mile than for average passenger vehicles. Expanding the geographical reach of the transit system would provide transit access to a higher number of residents and workers.
Page C-41 of the Climate Action Plan is even more specific, stating assumptions:
- 2.5% increase of transit network coverage
However the workings in the document Trans2 1 analysis_v4_080814.pdf don’t reflect either of these statements. While the plan makes grand statements envisioning an expanded regional bus service with increased frequency and ridership ICF’s workings tell a different story:
- 2012 Current Fleet: 81 vehicles
- 2020 Anticipated fleet: 81 vehicles
How the exact same number of vehicles are able to deliver this greatly expanded service proposed by the plan is completely impossible. This is important as the 81 vehicles split between:
- 26 smaller El Dorado buses (pictured right)
- The remainder are larger buses and reticulated buses that emit four times as much as El Dorado buses
There is no change in this split in the 2020 emissions calculations.
The plan to expand transit as already stated is likely to add vehicles to shoulder times, diminishing average ridership and increasing emissions per passenger mile. Potentially the expanded transit service may skew towards higher emitting vehicles – but this is not reflected in the calculations – the same split between vehicle types – large and small – is assumed.
Marin Transit itself does not appear to be planning to expand it’s service at all. In their clarifying email to ICF they state:
we do not have any future projections for bus occupancy, but I don’t believe it will change significantly in the next few years
Planning for Reality welcomes corrections and additional scrutiny of the above.