1. Although the causes of peak car travel are still not entirely clear, this analysis shows that it is not a new phenomenon but rather a fundamental shift in travel behavior that dates back two decades. As result, instead of continuing a “wait-and-see” approach regarding peak car travel, it may be prudent to forge ahead on the basis that this represents a permanent structural change. Further, the relationship between driving levels and the economy, once strongly- and positively-correlated, has undergone a revolutionary change such that, for most states, there is no longer any significant connection between the two variables. Since drivers pay only a portion of the true costs to drive 2-3, leaders should reconsider traditional transportation planning approaches since prioritization of automobile travel appears to be an investment with diminishing returns. Widespread – Not limited to one “type” of state: Occurring in 96% of states Evident in high-driving, rural states and in lower driving, urban states Predates impacts of Information Communication Technology (ICT): First peak in Washington in 1992 10 states peaked as of 2000 Permanent, “new era of travel” 1 : 20 years since first peak / 10 years since national peak 48 th state peaked in 2009 Timothy J. Garceau, Ph.D. Candidate, Department of Geography Dr. Carol Atkinson-Palombo, Department of Geography Dr. Norman Garrick, Department of Civil & Environmental Engineering Peak Car Travel in the United States: A Two-Decade Long Phenomenon at the State Level THE PEAK CAR TRAVEL PHENOMENON THE CHANGING RELATIONSHIP BETWEEN DRIVING & THE ECONOMY Figure 1: Peak car travel at the state level: Changes in driving levels from 1992 to 2011 Figure 2: Changes in Gross Domestic Product per Vehicle-Mile Traveled (GDP per VMT) for a four-state sample, 1980-2011 Earlier peak car travel states have higher efficiencies States with longer periods of growth in driving and higher rates of growth resulted in lower efficiencies per mile driven Table 1: Peak Car Travel Year & Regression Results for Gross Domestic Product per Capita and Vehicle-Miles Traveled per Capita at U.S. State Level for Three Decades ACKNOWLEDGEMENT We would like to thank the FHWA Technology Partnership Programs, Universities and Grants Programs for Dwight David Eisenhower Transportation Fellowship Funding. CONCLUSIONS REFERENCES 1Metz, D. Peak car and beyond: The fourth era of travel. Transport Reviews, Vol.33,No.3, 2013, pp.255-270. 2Puentes, R. and A. Tomer. The Road Less Traveled: An Analysis of Vehicle Miles Traveled Trends in the U.S. Brookings Institute, Washington, D.C., 2008. 3Zhu. P. and J.R. Brown. Donor states and donee states: investigating geographic redistribution of the US federal-aid highway program 1974–2008. Transportation, Vol. 40,No.1, 2013, pp.203-227. ECONOMIC-EFFICIENCY-PER-MILE-DRIVEN PEAK CAR TRAVEL PATTERNS IN THE U.S. Increasing Slowly (0-200 VMT per capita greater than prior year) Increasing Rapidly (>200 VMT per capita greater than prior year) Decreasing Rapidly (>200 less than prior year) Peak Year (Highest Value) Decreasing Slowly (0-200 less than prior year) 19921999 20112004 Decoupling in Majority of States: A Relationship Reversal? Four of five states with negative relationships were four of the first states to peak (Washington, 1992; Oregon and Kentucky, 1999; Utah, 2002) Despite Peak Car Travel, Gross Domestic Product has NOT peaked and economic growth is occurring without associated driving increases Notes: A) “Strong” Relationship: R. Sq. > 0.70** Significant to 5% level B) “Moderate” Relationship: 0.30 < R. Sq. < 0.70* Significant to 10% level 1980-1989  33 states with strong A, positive correlation**  6 states with moderate B, positive correlation* 1990-1999  37 states with strong A, positive correlation**  8 states with moderate B, positive correlation** 2000-2011  Relationship in 30 states becomes statistically insignificant