Driving growth outpacing population growth: A treacherous road ahead?

As of 2014, total U.S. population was 318.9 million, 18.9 million more people than what there were in late 2006 when domestic population reached the 300 million person mark. This breaks down to an average growth rate of 2.3625 million people per year, or a 0.7875 percent per-year growth. What the number doesn’t tell us, however, is how many births there were, nor does it reveal the number of deaths, only the growth rate overall.

Percent population growth being what it is, between Jan. 1 and Dec. 31, 2014, comparatively, the percent per-capita average VMT growth was 0.9 while total percent growth in VMT overall was 1.658, VMT in the aggregate rising from 2.966 to 3.016 trillion.

So, what this is saying is from Jan. 1 to Dec. 31, 2014 the rate of growth of both per-capita and total VMT outpaced the rate of growth of population; the ratio of average per-capita VMT growth to average annual population growth being roughly 1.14 to 1, while the ratio of average aggregate VMT growth over the year to the average annual rise in population being almost 2.11 to 1.

So, imagine if the number of driving miles clocked off – both in the aggregate and per-capita – dropped back to a percentage comparable to percent-population growth. Even better, what if motor vehicle miles driven retreated by the same proportion, equal in magnitude to that of the current increase? This would certainly have implications for improved air quality – no question. But, alas, such is not the reality.

In “America’s air: In a state of unhealthy repair?,” I referenced a study from the Massachusetts Institute of Technology and one of the study’s findings was such that the “total American air-pollution-related premature death rate” every year was about 200,000, and in citing information from a related MIT news release, I wrote: “‘Emissions from road transportation are the most significant contributor, causing 53,000 premature deaths,MUTCD_W8-5.svg[1] followed closely by power generation, with 52,000.’”

If this is indeed the case, what this means is that of all early U.S. deaths attributable to air pollution, 26.5 percent are transportation-associated or in some way has a transportation connection. That’s too high.

That the economy has mostly rebounded from the 2007-2009 period now known as the “Great Recession,” suffering a meltdown of sorts and total U.S. unemployment has eased to somewhere around 5.5 percent, on the flipside is that more driving – doubtless a sign of an improving economy and population increase – and air pollution and the early mortality and morbidity just from transportation-related causes alone, means the economic improvement has come with a cost. The per-person cost: 6 million dollars. Not good.

As with the “6 million dollars” reference, this too from: “Air: It is what it is and what it is, is not good”:

“In ‘Landmark California program could have huge emissions-reductions impact,’ in referencing a Cambridge Systematics, Inc.-prepared study in July 2009 for the Moving Cooler Steering Committee called: Moving Cooler: An Analysis of Transportation Strategies for Reducing Greenhouse Gas Emissions, I wrote: ‘Among effective strategies identified to mitigate deficiencies directly linked to the production of greenhouse gas and other emissions are: improve both motor vehicle and fuel efficiency, decrease the production of carbon coming from ignited fuels, reduce the number of vehicle travel miles and improve the transportation network.’”

Those answers, though as seemingly straightforward as they are, one can’t help but feel that these strategies are slow in coming MUTCD_R3-27.svg[1]which would make such fewer and farther between.

Leave a Comment