Combining Car Trips: Improve How You Move

by Fred Horch, Principal Advisor at Sustainable Practice

Americans take about four trips per day on average, more than 80% of them by car.

Almost everyone in the United States knows the price of a gallon of gas, because buying and burning it is how we move most things most of the time, including ourselves and the goods we buy. For more than four out of five trips, we drive a private vehicle. Not only that, but we often drive alone: the average vehicle occupancy in the United States declined from 1.87 people in 1977 to 1.5 people in 2019.

Combining car trips is the sustainability step in this action guide. Whether you drive fuel-burning or battery electric vehicles, try increasing the person-days per car start per week for your household or organization while getting where you need to go. (Confused by a “person-day”? Don’t worry, it’s easy to measure and I’ll explain how!)

Combining car trips can mean starting your automobile fewer times per week, carrying more passengers per trip, or sharing vehicle ownership — or all three!

We Really Like to Drive Ourselves

Data from the US Federal Highway Administration’s National Household Travel Survey shows how much we prefer to drive, compared to other modes of movement.