We've all seen public transportation buses pull away from bus stops in a cloud of black smoke. Here in sunny Austin, Texas, nearly 300 diesel-powered Capital Metro buses prowl around trailing this dingy haze every day. Given that the Austin area has exceeded the EPA acceptable amount of ground level ozone, and that Travis and Williamson county residents will now be forced to pay for expensive yearly vehicle emissions inspections, it's reasonable to ask if Capital Metro is doing everything it can to improve area air quality. How much pollution is in that ominous black bus fog?
Both gas and diesel engines contribute to smog. They emit oxides of nitrogen (NOx) and unburned hydrocarbons (HC, sometimes called VOC). These 2 ingredients cook in the hot afternoon sun producing smog and ground level ozone.
Diesel engines produce NOx and HC in prodigious quantities. Data supplied by Capital Metro and the US EPA show that each bus in Capital Metro's fleet emits an average of 23 grams per mile of these 2 pollutants. This can be compared to a 2005 Suburban at .27 grams per mile, or a 2005 Honda Accord at .07 grams per mile.
Capital Metro has a system-wide average bus occupancy of 7.1 passengers. This number can be used to express pollution data in a more understandable way.
Each bus is the pollution equivalent of 80 single occupant Suburbans, or 308 single occupant Accords.
In 2003 Capital Metro's bus fleet traveled 13.6 million miles in the Austin area, emitting 344 tons of NOx and HC into the region's air. Capital Metro's 291 buses are responsible for 1.2 percent of the area’s on-road pollution while only being .05 percent of the area’s on-road vehicles.
Senator Kay Bailey Hutchison recently announced that the Senate appropriations committee, of which she is a member, passed the 2006 appropriations for the Department of Transportation. Included in the pork in this bill is $4.2M for Capital Metro. Among other things, the money would be used to improve Austin air quality by retrofitting emissions equipment to Capital Metro buses.
Capital Metro can easily cut their pollution without a single federal dollar. The thing to keep in mind is that the more passengers Capital Metro carries, the more polluted our air comes.
The Central Texas Transportation Committee, a group of area Libertarians involved in transportation issues, has a plan for Capital Metro to help improve area air quality.
Eliminate low-ridership routes. In addition to helping pollution, this makes good fiscal sense. Taxpayers heavily subsidize Capital Metro routes, over $30 per passenger on some routes. Out of 109 routes, 32 average less than 4 passengers per bus. Routes 252 (Buckingham/Slaughter) and 100 (Saturday Airport Flyer) manage to average less than one passenger per bus. These routes should be dropped.
Eliminate free rides on Ozone Action days. The last thing Austin needs on high ozone days is a bunch of nearly empty buses on the street. Capital Metro should be required to make sure that all routes on ozone action days carry at least 10 riders per bus. At that rate the buses still emit much more pollution than if those 10 people were alone in an SUV, but it would be an improvement.
Eliminate the commuter rail plan. The commuter rail train will emit 103 grams of NOx and HC per mile. Even if it meets Capital Metro's ridership projections it is still far dirtier per passenger than a single occupant SUV. Capital Metro could buy a brand new Suburban for each of their projected 1000 initial riders for about $35M (half of what track modifications alone will cost) and make the air cleaner to boot. In addition, the city plans to concentrate low-income families along the polluted train route, especially near the stations, where pollution will be greatest.
The Clean Air Force, an organization of local politicians who created the vehicle emission inspection program for Travis and Williamson counties, is funded in part by taxpayer money from Capital Metro. The inspection program targets the cleanest segment of automobiles, those less than 24 years old, while ignoring the pollution contributed by Capital Metro's bus fleet. It's time for Central Texas taxpayers to demand that Capital Metro do its part in cleaning the air.
September 10, 2005
