LETTERS TO THE EDITORS
An Autonomous Trip
To the Editors:
Henry Petroski’s Engineering column on autonomous vehicles in the January–February issue was excellent. It made me think about a recent excursion and what it would be like traveling in an autonomous vehicle. The trip was from Ashburn, Virginia, to Grand Rapids, Michigan, and back again.
In Maryland, my family and I proceeded to I-70, where the speed limit ranged between 65 and 70 miles per hour. (Would the vehicle know to make this speed change?) In Pennsylvania, we made a rest stop. (How would you tell the vehicle to pull into the rest stop?) When we got to Breezewood, Pennsylvania, intending to get on the Pennsylvania Turnpike, we encountered a traffic nightmare. (How would the vehicle manage this complex interchange, which has multiple traffic lights?) To get onto the turnpike, you have to pass through toll gates. (How would the autonomous vehicle manage a toll road?) We then made a stop to get lunch and fill up on gas. (How would the vehicle park and then select a gas pump?) Traveling west, we proceeded to Plymouth, Michigan, and pulled under the portico of the motel to unload baggage and check in. (How would the vehicle know to pull under the portico, and then to find a parking place?) The next morning we drove to Canton, Michigan, to join up with additional family members. From there, we headed westbound on our way to Grand Rapids, Michigan. Fortunately, we listened to the radio for traffic information. Our direct route was closed down due to a 40-vehicle crash on black ice. So, we took a circuitous route to avoid it. (What would an autonomous vehicle do in this situation?) When we got to our hotel in Grand Rapids, we turned the vehicle over to the valet for parking. (How would an autonomous vehicle park in a parking garage?)
During our stay, it snowed heavily. On the way back, the road was covered with slush, and the lines on the road were covered up. (How would an autonomous vehicle navigate without lines to guide it?) With all these challenges, I cannot envision how an autonomous vehicle could make this trip.
William Bagaria, Jr.
Professor Emeritus, U.S. Naval Academy
Dr. Petroski responds:
Professor Bagaria asks some interesting and challenging questions. Autonomous vehicles may never be able to do some of the things he asks about, such as driving in snow that obscures lane markings. In such a case, the vehicle may ask the human driver to take over or pull off the road. But his other questions are already answered in the affirmative by features incorporated into current GPS navigation tools, such as knowing when the speed limit on an interstate highway changes. The human driver is not likely ever to be totally replaced, and a decision of when to exit for a rest stop may always have to be implemented by giving a voice command or overriding the autopilot mode.