Is Travel Behavior Changing? What the New Data Says

Source: VMT - http://www.fhwa.dot.gov/policyinformation/travel_monitoring/14dectvt/14dectvt.pdf

A number of observations are in order:

• Fuel prices and a soft economy were important contributors to slowing VMT in the past decade, but the body of evidence suggests that other factors were also contributors. The population is slightly more urban with lower travel levels, millennials are traveling less, and people are substituting communications for travel with growth in e-commerce, e-learning, telecommuting, and texting and messaging in lieu of some social travel. Thus, a stronger economy and lower fuel prices are likely to restore some but not all of the historic growth in travel demand.
• Declines in travel over the past several years included disproportionate declines in non-urban travel and in freight travel. These components are significantly impacted by both economic activity and fuel prices. Both are subject to rebound with a stronger economy and moderating fuel prices. 
• Year-over-year comparisons of VMT have been on a general upward trend since 2008 and have been in positive territory the past three years. Transit ridership trends remain positive but the magnitude of year-over-year changes have been on a declining trend since 2011.
• Based on a visual analysis of Figure 1, transit ridership has generally responded positively to labor force growth.

Figure 2 - Monthly Trends in VMT, Ridership and Fuel Cost

• It is premature to draw conclusions regarding the impact on either VMT or transit ridership due to the decline in fuel prices. The decline occurred relatively late in 2014. Preliminary speculation suggested consumers were paying down debt or increasing savings with the fuel cost savings initially. Only time will tell as to the duration of lower fuel prices and the longer-term reactions of consumers to prices.

The country has had the benefit of seven years with travel demand below its 2007 levels. During this period, some progress was made in expanding the capacity of the roadway system such that congestion levels improved in many locations. Going forward we face a great deal of uncertainty regarding both the demand for travel on roadways and transit and the level of service and condition of our roadway and transit systems. Unfortunately, this seven-year pause was not leveraged as an opportunity to put our house in order regarding long-term transportation funding and investment priorities.

Going forward, roadway travel demand growth is unlikely to resume at the same pace it had in the latter half of the 20th century. However, prospects that the absolute and per capita declines in VMT we witnessed in the past decade are repeated are unlikely unless there is a very unattractive economic future. While communication substitution has and will continue to play a role in moderating travel demand, as might the continued urbanization of the population, the desire to travel remains highly linked to the economic ability to participate in activities. If the large segments of society that have not had real income increases began to benefit from an improved economy there will be few that won’t desire to take advantage of additional vacationing, shopping, dining out, etc. and traveling to avail themselves of these pleasures. Communities across the country are attempting to attract new businesses, encourage tourism, re-energize manufacturing, and stimulate real estate development. These initiatives and their subsequent activities will generate additional travel. While more moderate overall travel demand growth is likely, it is imprudent to presume there will not be growth in roadway travel demand absent harsh economic conditions that few predict and no one aspires to.

Travel demand growth in both roadway and transit use are likely to vary dramatically across geography in response to demographic and economic conditions as well as respective levels of service. Prudent use of scarce resources will require a great deal of caution in investment programming. While no communities like to plan for decline, there are certainly many areas that would be prudent to rationalize their infrastructure investments in transportation relative to their fundamental demographic and economic conditions or risk being unable to maintain their infrastructure. 

There will always be a strong temptation to use infrastructure investment in the hope that it will stimulate development demand (i.e., the "build it and they will come" argument). A prerequisite for transportation that shapes or stimulates development, however, is a fundamental market demand for additional activity in the target location that could then benefit from that infrastructure. Good transportation can be a part of the quality of life that influences growth but it cannot singlehandedly trump several other factors that drive fundamental demographic and economic trends.

Analysts and the media are anxious to interpret each new piece of data on demographics and transportation in the context of how it plays against various critical planning and transportation policy issues. While such interpretations are inevitable and relevant in attempting to understand needs and influence policy and funding initiatives (such as federal transportation funding reauthorization), a great deal of caution should be used—trends are often subtle and highly complex, and data are limited and often subject to refinements. 

Whether prognosticating about peak auto, stereotyping Millennials as urban-centric, alternative mode pioneers, envisioning Uber and other transportation network companies replacing personal vehicles, or anticipating that autonomous cars will render transit irrelevant—have fun speculating what the future will be like, but exercise caution when extrapolating observations and limited data into long term trends. Two or three anecdotes do not make a particularly robust foundation for policy decisions. Seeing something reported in the media several times doesn’t make it valid.

The January 2015 estimated VMT was just released. VMT was approximately 5 percent above January 2014. Perhaps we will have news headlines include such breathless conclusions as "Driving Is Back," "Gas Prices Matter," "People Are Using Those New Cars They Bought," and "Millennials Are Assimilating." But maybe we should wait for a few more months before drawing too many conclusions.

The opinions are those of the author—or maybe not—but are intended to provoke reflection and do not reflect the policy positions of any associated entities or clients. [email protected].