Parking is a bit like milk: We don’t think much about it until it’s not there. But the humble place of parking in our lives should not be underestimated. When we talk about driving, for example, we’re really talking about parking—the average American car sits parked more than 90 percent of the time. And you might be surprised at how much city driving is actually the search for parking: Studies have shown as much as a third of downtown traffic is simply drivers looking for on-street spaces.

In most places, it’s actually not that hard to find a spot. A Purdue University geographer mapped his local—and fairly typical—county and found that there were three times as many parking spots as there were people.

But raw numbers don’t explain how people feel about parking. Parking authority Donald Shoup described a study done at a West Hollywood garage. On the bottom floors, he said, there were parked cars, and in the empty spaces, plenty of oil stains to indicate past users. The upper floors looked as though they had never been graced by a single car. Yet drivers complained there was “nowhere to park.” Drivers’ perception of parking supply is informed by the parking spaces they can actually see.

Welcome to the psychology of parking. Let’s consider looking for parking at a local shopping mall. Do you sail into the first available spot, even if it’s in a windswept, no-cell-phone-service corner of the mall, the place where all the snow is pushed in the winter and where all the rogue shopping carts congregate in the summer? Or do you endlessly circle the rows, looking for that bronze-enshrined parking spot of a lifetime, perhaps even car-stalking an exiting shopper as they walk to their space?

A biologist—inspired by the ways animals forage for food in the wild—found that drivers who followed a “pick a row, closest space” strategy actually got inside the store more quickly than drivers who “cycled” for the most advantageous spot. Perhaps people simply misjudged the time and distance. Planners have found that people seem willing to walk about a half-mile from a parking spot to a destination. But they’re more apt to do this in a big parking lot, where the destination is in sight, than on city streets, where the endpoint may be a few turns away—the distance actually feels longer.

How about when you glimpse someone about to vacate a spot? Have you ever had the feeling that they were being deliberately pokey, conducting a 10-point safety check—maybe a touch of nasal depilation—before offering up their spot? You would not be wrong. Studies have found drivers actually took longer to vacate their space when another driver was waiting than when one was not. What to do? I have no answer—this may be hard-wired human instinct. But I can tell you what not to do: Pressure the other guy. A honk from the waiting driver, or even a creep forward—the auto equivalent of an “ahem” cough—seemed to slow the departure process even further.

Tom Vanderbilt is author of Traffic: Why We Drive The Way We Do (And What It Says About Us). Visit his Website at tomvanderbilt.com/traffic.