Why Are Some Parking Lots Arranged Diagonally And Others Are Straight?

What's the logic behind parking lots? Why are some arranged diagonally, and others laid out straight? It turns out that there’s a lot more to parking lot design than simply painting lines on a sheet of asphalt. Complex decisions regarding spacing, number of spots, efficiency, and flow of traffic all go into creating the perfect place to leave cars. The science of how parking lots are arranged is fascinating.

Take a drive through any city, and you'll likely notice lots with diagonal versus straight parking spots. Why parking lots look different has a lot to do with how the lot is used. Different angles change the amount of spots available in any given lot, and can impact how quickly drivers can get in and out of spaces.

But what angle of entry is best? Should traffic be one-way or two-way? How many shopping cart corrals does one truly need? All of these choices, and more, are made by the great mathematical minds behind parking lots.

  • It's All About Efficiency And User Experience

    It's All About Efficiency And User Experience
    Photo: Dwaynep2015 / via Wikimedia Commons / CC BY-SA 4.0

    There are plenty of things to consider when designing a parking lot, but much of the decision-making boils down to three aspects. First is the total number of spaces - usually, you'll want to maximize the space to maximize potential visitors or customers. Second is the width and direction of traffic lanes, which help determine how efficiently a parking lot operates.

    Finally, the ease of entry and exit, both in relation to parking spots and the lot itself, makes a real difference in how "user-friendly" a parking lot is.

  • 90 Degree Parking Maximizes Spots

    The standard option for a parking lot is the perpendicular, 90 degree model. This means that a driver has to turn their vehicle a full 90 degrees from the traffic lane in order to enter their parking space. This model has the benefit of pure space efficiency, as it’s the best way to include a maximum amount of parking spaces on any given lot.

    However, the big turns required to use a parking lot like this necessitate that space be taken up elsewhere, because it requires two lanes of traffic within the lot rather than one. People like these parking lots because they’re simplistic and everyone is used to them, but they’re not always the best option.

  • 60 Degree Parking Is A Safe Bet

    The 60 degree parking lot model - which requires a turn of about 60 degrees to enter a slightly angled parking space - is considered a good middle-ground amongst parking lot designs. These parking spaces still require a decent amount of turning to enter into, and thus require two lanes of parking traffic, but they help make space for those lanes with their angled design.

    A 60 degree turn is easier to pull off than a 90 degree turn, so parking lots like this are less likely to see people moving back and forth trying to fit into spots.

  • Mathematicians Recommend 45 Degree Parking

    Mathematicians Recommend 45 Degree Parking
    Photo: WhatWasThere / via Pinterest

    The best design for parking lots seems to be the 45 degree model, although it has its drawbacks. The spaces aren't as efficiently placed as those in a 90 degree model, but the 45 degree method only requires a single lane of traffic to operate. The entry and exit from these spaces is incredibly easy, requiring a small turn and very little maneuvering space.

    These lots are safer, because drivers only need to worry about one direction of traffic, and more efficient because everyone is working in the same direction. Mathematicians prefer this version of a parking lot, too.