THEGREENGROK    Statistically Speaking

Statistical Grok: Gas Prices Impact Miles Driven … Finally!

by Bill Chameides | June 20th, 2008
posted by Erica Rowell (Editor)

Permalink | 2 comments


With gas prices way up, the number of miles Americans are driving is down.

The increase in gas prices is a drag — no question. But there is a silver lining. During the 1990s and the early part of this decade, cheap gasoline fueled our addiction to oil and SUVs and jacked up our ever-increasing highway miles. But things have changed. Americans are driving less and buying more fuel-efficient cars, and oil imports are down. Let’s look at the numbers.



Average Cost of Regular-Grade Gasoline in the United States

For all of 2007: $2.71
March 2008: $3.21
April 2008: $3.44
As of this posting: $4.04
August 2008 (projected): $4.15
For all of 2008 (projected): $3.78

Traffic Volume in the United States

Cumulative change for 2007 relative to 2006: -0.4%
Cumulative change for 2008 relative to 2007: -2.3

Only year since 1942 in which traffic volume decreased during the month of March: 2008
Month with the largest recorded percent decrease in traffic volume: March, 2008 (-4.3%)

U.S. Average Car Sales and Fuel Economy


Percent change in sales April 2007 to April 2008


GM truck and SUV sales: -27%
Ford SUV sales: -36%
Ford Focus sales: +44%
Toyota Prius sales: +54%
Highway gas mileage for Ford Expedition: 18 mpg
Highway gas mileage of Ford Focus: 33 mpg
Highway gas mileage of Toyota Prius: 45 mpg
Projected change in U.S. petroleum consumption in 2008: – 1.4%


U.S. Department of Energy –
U.S. Department of Transportation –
U.S. Energy Information Administration, Petroleum Price Data and Analysis-
U.S. Federal Highway Administration –
Washington Post –

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  1. Bryn
    Jun 25, 2008

    A letter I’ve sent to the editors of various local newspapers: Gas stations across the Triangle await their shipments of 4s for their signs. Local and regional government agencies discuss the best ways to get more people more places without their cars ( Regional employers from Glaxo Smith Kline to Blue Cross offer discounts to their employees when they buy bus passes ( North Carolina State University joins UNC, Stanford, Dartmouth, and the University of Pennsylvania, among others, in offering free annual bus passes to all employees. Harvard, Tufts, and Cornell offer discounted passes, and Rutgers, Princeton, and Yale offer a pre-tax purchase option. Colorado State University, which also offers free bus passes, has done a study of several university campuses and has found that in many instances, it is cheaper to subsidise one employee’s bus pass than it is to build another parking space for that employee ( Duke University shares many wonderful traits with these neighbouring and peer institutions, but it has not yet offered discounted or free bus passes to its employees. This benefit would help not just Duke, but also Durham and the larger Triangle community by easing traffic congestion, improving air quality, and lowering driving-related stress for its employees, as well as helping increase funding for transit services. Much of the funding for transit services is calculated by the number of riders a service has. The more riders, the higher the funding levels, regardless of whether those riders pay a fare when they board or not. Duke’s admirable commitment to becoming a greener campus can continue to extend beyond the boundaries of the campus itself when it decides to join its peers and corporate neighbours and offer discounted or free bus passes to its employees.” title=”Duke would benefit from offering bus passes to its employees

  2. Beth
    Jun 25, 2008

    I read this and thought it was particularly apt:” title=”Politics of Oil

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