The Strategy of Parking
Science settles the argument of whether to cruise or grab the first spot
After pulling into a parking lot, John E. Kobza takes the first spot he sees. His wife tells him, a specialist in transportation efficiency at Virginia Tech, that it doesn't make sense to do it that way because empty spaces usually turn up closer to the door.
To settle the argument, in 1995 Professor Kobza turned the problem over to C. Richard Cassady, then a Virginia Tech graduate student and now an assistant professor at Mississippi State University. Cassady chose as the quintessential study site a Wal-Mart in Christiansburg, Va., not far from the university campus in Blacksburg. It was, by no coincidence, where Kobza often shopped.
Despite great strides in defining the law of total probability, queuing analysis, and discrete-time semi-Markov chain mathematical logic, no one had ever tackled one of the foremost problems of our time: how to find a parking place. So he wrote pages of equations as he analyzed two strategies, described to the right.
The winner is Pick a Row, Closest Space if your goal is to get from the parking lot entrance to the front door of the store fastest. Cycling cuts the walk by 27 percent in his Wal-Mart test case.
Kobza's wife, Kathy, says science be damned. When she's at the wheel, she still looks for the space closest to the door.
Parking lot psychology A recent study analyzes the advantages and disadvantages in two methods of finding a space in a shopping mall parking lot. 1. Pick a Row, Closest Space--for people who want to park in a hurry: Choose a convenient parking row and take the best spot available, even if it's at the far end of the lot. 2. Cycling--for people who hate to see a closer space after they've parked: Pick a convenient row and hold out for a spot near the front. If none is available, go to the next row and seek a close-in spot.
Results From lot entrance to parking space Pick a Row: 37.7 seconds Cycling: 52.5 seconds
From lot entrance to the store's door Pick a Row: 61.3 seconds Cycling: 70.7 seconds
Average walking distance to store Pick a Row: 257 feet Cycling: 200 feet
Source: Transportation Science
This story appears in the April 27, 1998 print edition of U.S. News & World Report.
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