Socioeconomic and Travel Demand Forecasts for Virginia and Potential Policy Responses: A Report for VTrans2035: Virginias Statewide Multimodal Transportation Plan

摘要

VTrans2035, Virginia's statewide multimodal transportation plan, requires 25-year forecasts of socioeconomic and travel activity. Between 2010 and 2035, daily vehicle miles traveled (DVMT) will increase between 35 percent and 45 percent, accompanied by increases in population (28 percent to 36 percent), real household income (50 percent), employment (49 percent), transit trips (75 percent), and enplanements (104 percent). Of the 2.27 to 2.87 million additional Virginians forecast by 2035, most (1.72 to 2.34 million) will settle in one of four planning district commissions (PDCs). These PDCs, and their expected population increases, are George Washington Regional (0.25 to 0.28 million), Richmond Regional (0.33 to 0.41 million), Hampton Roads (0.31 to 0.41 million), and Northern Virginia (0.83 to 1.23 million). Virginia will likely see the number of people age 65 and over double from 1 million at present to 2 million in 2035. Four potential policy responses to these forecasts are given in this report: (1) encourage increased density at select urban locations to reduce CO2 emissions; (2) use cost-effectiveness as a criterion to select project-level alternatives for achieving a particular goal; (3) identify policy initiatives to serve increased demographic market segments, and (4) quantify the economic harm of general aviation airport closures. These policy responses are not the only ones feasible but were selected because they necessitate the interagency coordination that is the premise of VTrans2035. The first two policy responses demonstrate limited but real promise. The first may reduce DVMT by 1.1 percent to 6.4 percent of the baseline 2035 DVMT forecast, for a reduction of 1.507 million metric tons of CO2 annually. Yet DVMT is affected to a greater degree by factors over which decision makers exert less influence than with density. For example, the 2035 baseline DVMT decreases by 7 percent if an alternative population forecast is assumed; 10 percent to 65 percent if real household income remains relatively flat; and 49 percent to 82 percent if fuel costs increase to 10/gal by year 2035. Thus, the best estimates of travel activity are highly sensitive to underlying assumptions regarding economic conditions, and the report accordingly documents, for each desired forecast, a range of possible values. The analysis of the second policy response found that the cost-effectiveness of plausible alternatives in a hypothetical case study varied by a factor of 3. By extension, this finding suggests that an ability to choose project alternatives based solely on each alternatives ability to meet a single goal or a limited number of goalsand without constraint by funding source (e.g., highway or transit, capital or operations)can increase the cost-effectiveness of a project.