Exploration of Technical Developments and Data Sources that May Have Implications for Long-Range Transport Planning in Virginia

About the report

VTrans is the Commonwealth of Virginia’s statewide multimodal transportation plan. Virginia’s Office of Intermodal Planning and Investment maintains the plan under the supervision of the state’s Commonwealth Transportation Board. The plan’s methodology uses several VTrans “trend trackers” that are quantifiable metrics updated annually; “macrotrends,” which are emerging patterns of change; and Commonwealth Transportation Board objectives, or qualitative targets for which the Office of Intermodal Planning and Investment defines various metrics. The research reported herein supported the Office of Intermodal Planning and Investment’s mission through three tasks related to these trackers, macrotrends, and objectives: (1) compile statistical series, historical values, and future forecasts to represent seven trend trackers in the VTrans framework; (2) estimate the differences between forecast and observed values for population and employment; and (3) investigate the possible means of using one or more of the trend trackers in a planning application. Forecast data purchased from Woods & Poole Economics, Inc., coupled with data from publicly available sources and a review of the literature, formed the basis of the analysis.

The data from Woods & Poole support several VTrans trend trackers pertaining to population, employment, growth of professional and technical services, and population aged 65 and older. For instance, during 2020 through 2040, Virginia’s population aged 65 and older is forecast to grow at an annual rate of 2.02%—nearly three times the forecast annual rate of the total population (0.69%). In addition, an analysis of input-output expenditures suggests that summing employment in three sectors—wholesale trade, retail trade, and transportation and warehousing—may support one of the trend trackers for macrotrend 5, the number of jobs in goods movement-dependent industries.

Woods & Poole generate forecasts of future population, employment, and personal income statistics for 105 regions in Virginia, each consisting of one county, one city, or one county plus one or two small cities and defined by the Bureau of Economic Analysis for statistical purposes. Population forecasts generated from 2014 to 2022 showed root mean squared differences between the forecast and the finalized estimate (2 years ex post) ranging from less than 1% to 10.20%, with population forecasts of more remote future years (e.g., 6 to 8 years away) tending to have larger errors than forecasts of closer impending future years (e.g., 1 to 2 years away). Employment forecasts generated from 2014 to 2022 showed root mean squared differences between the forecast and the finalized estimate ranging from 2.63% to 21.18%. Employment forecasts of more remote years tended to have larger errors; however, this pattern was much “noisier” than the pattern in the population forecasts. Personal income forecasts exhibited a quantitative performance similar to that of the employment forecasts.

This report found four examples of ways in which local planners might employ the VTrans data as a planning resource: (1) use population forecasts to predict if and when density for rural areas will increase to a level sufficient to support fixed-route bus service; (2) use income forecasts to estimate the fraction of households that will not have access to a vehicle; (3) use income and population density forecasts to predict changes in right-of-way costs; and (4) use employment and population forecasts to forecast changes in the ratio of the number of jobs divided by the number of residents (i.e., jobs-housing balance).

_{Disclaimer Statement:The contents of this report reflect the views of the author(s), who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement.}

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