Proposition I - MUNI Diesel Bus Replacement

Voter Guide
This measure appeared on the March 2004 San Francisco ballot.

What it does

This ordinance attempts to force Muni to use a different kind of bus, one that is less polluting than those used in their current fleet. If it is adopted, and legally enforceable, it would require Muni, during the two years between December 31, 2004 and December 31, 2006, to remove from active or reserve service and no longer operate any diesel bus that has exceeded its 12-year useful life, currently 151 buses out of a total diesel fleet of 550. It further provides that if replacement buses are not commercially available or other unforeseen circumstances prevent Muni from procuring new buses on a timely basis, a single 12-month extension may be granted by the vote of 8 of the 11 Commissioners of the San Francisco Transportation Authority. (The Commissioners are the members of the San Francisco Board of Supervisors.) The measure does not provide funding for Muni to fulfill this mandate.

Why it is on the ballot

Between 1997 and the end of 2003, Muni, through bus replacements, has reduced its aggregate particulate matter (PM) emissions by 88% and its oxides of nitrogen (NOx) emissions by more than half. Nevertheless, some of the members of the Board of Supervisors and various environmental groups have been pressing Muni for several years to remove from service all of its diesel buses. In 2001 Muni proposed replacing 80 old diesel buses in its fleet with new "clean diesels" that have exhaust traps to capture PM and NOx emissions. Had Muni undertaken this replacement program, aggregate fleet PM emissions through 2003 would have been reduced by 98% and NOx emissions would have been reduced even below their current level. The Board of Supervisors rejected this replacement program, because it wanted Muni to pursue alternate fuel buses, such as hybrids and natural-gas-fueled vehicles.

During 2001 and 2002, Muni undertook an alternative fuels pilot program in which it tested the effectiveness and reliability of buses running on compressed natural gas (CNG) and hybrid diesel-electric. The tests showed that CNG buses were both unreliable and largely unable to fulfill the hill-climbing requirements of intensive operation in San Francisco; however, hybrid diesel-electric buses were able to meet Muni's performance requirements and would significantly lower Muni's overall fleet emissions. As a result of this study, Muni is now actively pursuing the certification of hybrid buses by the California Air Resources Board (CARB), and when certification has been obtained, intends to procure such buses.

The environmental groups behind this ordinance do not trust Muni to make the change to cleaner vehicle technologies on its own.


Those who support this measure state:


  • Diesel particulate matter is an air contaminant with the potential to cause cancer and other diseases; the elimination of diesel buses will reduce the amount of this contaminant.
  • Muni, as one of California's largest public transit systems, should be a leader in the implementation of clean bus technology.
  • Without the direction and requirement contained in this Ordinance, Muni management will not give sufficient urgency to the implementation of clean bus technology.
  • Because of bureaucratic inerti      a, Muni is not able to adapt to new vehicle types that reduce emissions. Without a push from the outside, Muni will be slow to change.


Those who oppose this measure state:

  • This measure in itself creates, and will as precedent create in the future, divided responsibility for the management of Muni, which is contrary to the clear intent of the voters when they adopted Prop. E in 1999 transferring management of Muni to the Metropolitan Transportation Agency.
  • Muni management is dedicated to reducing pollution from diesel buses, as demonstrated by its record over the past six years. It has formulated a plan that it is actively and concretely working to bring to fruition within the next few years, to replace the existing diesel fleet with a low pollution fleet of hybrid buses.
  • The enforcement of this ordinance would most likely cost the City as much as $20 million and would result in a substantial reduction in Muni service, thereby increasing automobile trips with their attendant pollution.
  • Even without removing from its fleet the diesels required by the Ordinance, Muni is currently, and will continue to be through 2007 and beyond, in compliance with all CARB, State, and Federal emission requirements.
  • There is no Federal funding available for replacing a transit operator's reserve fleet. It makes more sense to follow standard industry practice with the reserve fleet, which is to shift buses into the reserve fleet as they are replaced by newer buses.
  • There remains significant risk that CARB will not, in fact, certify diesel-electric hybrids, which could force Muni to buy demonstrably unreliable technology, probably CNG vehicles. CNG buses may work in cities like Sacramento, with few riders and stops that are much farther apart than the intensive service we provide in San Francisco, but Muni has tested CNG buses and found that they will not work here.
  • Even if CARB were to approve vehicle types that would allow Muni to comply with this law tomorrow, there is no way Muni could in reality comply with the deadlines. The procurement process for public transit vehicles takes at least three years. On this very practical level, the ordinance is not implementable.

SPUR's analysis

The legality of this ordinance is questionable because it purports to dictate a particular aspect of Muni's equipment acquisitions and operations even though Prop. E, adopted as a Charter amendment by the voters in 1999, transferred to the Municipal Transportation Agency (MTA) exclusive jurisdiction over these kinds of Muni capital-improvement and operational decisions. This measure is directly in conflict with Prop. E, and in fact undermines that measure's intent of moving these sorts of operational decisions away from political decision-making and into the hands of professional management.

On the merits of the Ordinance, if Muni is unable to meet the diesel replacement deadline, and were the Ordinance enforced, the City Controller has opined that the replacement of the 45 diesel buses in the reserve fleet would cost $20 million more than Muni plans to spend on upgrading these buses.

By the Ordinance-established deadline, it is highly likely that compliance with the Ordinance will require a drastic reduction in the bus fleet with a consequent dramatic reduction in service. On the other hand, if the MTA is given the time to procure hybrid diesel electric buses, the City will be able to meet its goal of significantly reducing air pollution caused by the current diesel fleet by procuring the hybrid diesel-electric buses that meet Muni's performance and reliability standards.

We are sympathetic to the concerns of the proponents. They are right to point out that, many times, Muni only optimizes for itself and does not pay enough attention to the externalities of its actions. (We see this with the design of bus maintenance yards, which have poor urban design and make inefficient use of land.) On the other hand, this measure optimizes for emissions and fails to take account of other critical issues. Not only is it a direct attack on Prop. E, the Muni reform measure we worked to hard to pass, but if implemented, would have a serious effect on service levels. The most important thing to do to make the city more environmentally sustainable is to attract a large number of new riders away from their cars and onto public transit. Anything that negatively affects reliability and service levels is going to dissuade people from riding Muni, and this we cannot support. Ultimately, Muni is going to move toward lower-polluting vehicles; the only thing at stake is how quickly. We believe strongly that the right answer for the environment is to adopt cleaner propulsion methods that will not reduce the reliability of Muni as the transportation provider of first resort.

SPUR recommends a "No" vote on Proposition I.