Self-driving or “autonomous” vehicles (AVs) will have passenger travel, freight trade, and emissions impacts. AVs and shared autonomous vehicles (SAVs) are expected to increase vehicle-miles traveled (VMT) by shifting some air travel to relatively long ground trips and adding more vehicle-trips to all roadways (including trips by those presently unable to drive). A Year 2020 survey of 1,004 Americans explored long-distance travel choices with and without AV options, and was coupled with the recent National Household Travel Survey (NHTS) dataset (for trips over 75 miles each way) and the rJourney synthetic trip data set (for US passenger trips over 50 miles each way).
This presentation will explain how count models to predict travel-party size (persons per long-distance trip) show long commute trips, business and shopping trips (and those destined for more population-dense destinations) carrying fewer persons than those for personal, social/recreational, school, and medical reasons (after controlling for trip distance, respondent demographics, and other factors). Younger, more educated, full-time workers and male drivers are more likely to select AVs and SAVs for their long-distance trips (everything else constant). Nationwide destination-zone choices depend on trip purpose and land use attributes at the trip end (as well as travel costs, across modes). Applications of rJourney’s 1.17 billion long-distance passenger trip data (synthetic for Year 2010) suggest that AVs and SAVs will eventually dominate U.S. passenger travel between 100 and 500 miles (one-way), person-trip distance averages will rise nearly 10 percent, and domestic passenger-miles by air will fall by over 50 percent, ceteris paribus, for an overall 6.7% reduction in domestic passenger-miles travelled (relative to a “business as usual”/no-AVs trend scenario).