Motor-vehicle-pollutants portion rising?, falling?, what?!

Consult most news sources these days – this one included – when it comes to poor air quality, and what you’re likely to uncover is that more often than not in the blame-game, traffic – more specifically, tailpipe emissions – is named. Obviously, not the only source of pollutants, nevertheless, the portion of pollutants coming from traffic – and transportation, more universally – is sizable.

Falling gasoline prices: What effect is this having on both motor vehicle and public transit use and, by extension, what, if any, impact has the decline had and having on the quality of our air.

David Levinson in “Mount Transit, Mount Auto, Mount Next,” at the Transportationist Blog, clues us in.

“In the US, we have seen a great struggle play out in the twentieth century between what David Jones calls Mass Motorization and Mass Transit. The conflict between the modes continues to this day, and has become a morality play in the culture wars. While they mostly serve different markets, they compete for users, and roadspace, and funding, and the hearts and minds of travelers. They are competing on old turf though, …, both modes appear to be in decline, transit for decades, the decline of the auto-highway-system is just beginning.”

This is an interesting revelation, because what this tells me is pollution from both sources should be becoming less and less, that is, as long as the mode-split-relationship (and other influencing factors) has not significantly varied.

To this, the U.S. Department of Transportation, Federal Highway Administration, Office of Highway Policy Information, says what? In its “Highway Statistics Series,” compiled is statistical data on “State Motor–Vehicle Registrations – 2012” and tabulated in this is motor-vehicle-registration data for all 50 states and the District of Columbia.

In the table’s far lower right-hand corner is the number: 253,639,386. This represents the total number of registered motor vehicles in the United States – as of 2012, of course.

Additionally, from the same “Highway Statistics Series,” presented is statistical data on “Net Volume (Gallons) Taxed (1961 – 2012).”

Based on the information presented, one could conclude from this that the amount of gasoline taxed is also representative of the amount sold. If memory serves me correctly, we did not start seeing the cost of gasoline plummet precipitously until around Sept. 2014.

At any rate, the amount of gasoline taxed in 2012 was: 169.640 billion gallons. It is what it is.

But, then I noticed something interesting. The overall trend was positive between 1961 and 2007, taxed gallons going from 60.006 billion in 1961 to 177.394 billion in 2007. After the Great Recession hit just subsequent to this, the number of gallons of gasoline taxed dropped to 171.229 billion in 2008, dropping even more to 168.551 billion in 2009, rose again in 2010 to 171.101 billion, falling to 168.722 billion in 2011. Only if there are fewer less-fuel-efficient vehicles on the road coupled with greater use of cleaner-burning fuels and/or less traffic on the roads coupled with greater use of cleaner-burning fuels – along with the dip in the amount of gallons of gasoline taxed, am I able to conclude that emissions emanating from motor vehicles are also fewer. That’s a good sign even if the number of motor vehicles on America’s roadways experiences level or upward growth.

However, should any of the variables appreciably change in a negative direction, such as in more gas being sold/used, a return to former buying habits as in there being increased purchases of less-fuel-efficient vehicles made, and/or more on-road delay encountered, then it is presumed a rise in transportation-sector emissions would follow. Lower gasoline prices could result in any or all of that coming about.

Levinson, in his blog post, meanwhile, opined, “The economy and gas prices still fluctuate, and a boom year with low gas prices following a recession with high gas prices might very well temporarily bump traffic upward, but that is really short-term noise. In the absence of external events (technological shifts, demographic shifts, social shifts), the curve appears to have peaked. But over the longer term, a significant technological shift could profoundly change how people use the automobile. If there were only one possible significant technological or social shift, this might be predictable, but there are numerous technological and social shifts in play.”

On transit use, the American Public Transportation Association (APTA) reported, in 2013, a record 10.7 billion trips were made, the highest patronage numbers transit in America has seen in 57 years.

And added: “While vehicle miles traveled on roads (VMT) went up 0.3 percent, public transportation use in 2013 increased by 1.1 percent.”

The public transportation membership association went on to point out that from 1995 on, “transit ridership is up 37.2 percent, outpacing population growth, which is up 20.3 percent, and vehicle miles traveled (VMT), which is up 22.7 percent.”

All of which has an effect on the level of emissions pouring into the air from overland modes of transport.

– Alan Kandel