Impact of autonomous vehicles on long-distance travel mode and destination choices in Texas

Privately owned and shared autonomous passenger vehicles (AVs and SAVs) and autonomous heavy-duty trucks (ATrucks) are expected to one day be widely available across the US and other nations. This study extends Texas' Statewide Analysis Model (SAM) to compare scenarios with and without AVs, SAVs, and ATrucks, while restricting empty AV and ATruck travel-only SAVs are allowed to operate without passengers. Results suggest that, on average, individuals are likely to choose more remote destinations, as seen by an 18% rise in (average ) long-distance (over 50 miles, one-way) business trips (from 121 to 142 miles) and 13% for non-business trips (from 135 to 151 miles). AVs and SAVs accounted for 14% of one-person (single-occupant) long-distance trips across Texas, contributing to a 17 percentage-point reduction in long-distance trips made by human-driven vehicles. For (one-way) person-trips between 50 and 400 miles, SAVs carrying 3+ passengers accounted for 14.4% of the total daily statewide (310 million) person-miles traveled (PMT), two-passenger SAVs made up 7.8%, and one-person AV trips represented 10.7%. In the freight sector, ATrucks were the preferred mode, handling 35% of freight ton-miles, surpassing rail at 24% and human-driven trucks (HTrucks) at 16% (vs 52% and 33% via HTrucks and rail, respectively, before the inclusion of ATrucks). Results suggest serious congestion issues if travel demand management measures are not implemented, with statewide daily VMT rising 24% (from 1.10 to 1.36 billion vehicle-miles) and distance-weighted average network speeds falling 37% (from 25.8 to 18.9 miles per hour).