How not to setup a car park!

I have had reason to visit QUT a few times recently and have been stunned at the bizarre setup of their short-term car park under the SE Freeway. It operates on a pay-and-display system; you park and then go to the machine and buy some number of hours and then put the ticket on your dashboard.

So, what's wrong with that, you say? Well, nothing is wrong with that system in general, but it doesn't work very well given the unique structure of the QUT car park.

Being under the freeway, the car park is very long and thin with a single narrow one-way road running down the middle with the parking areas to the left and right, broken in sections because of the supports for the freeway overhead. So when you enter it, you can see what car parks are available in the first couple of sections, but beyond that your view is obscured and you cannot tell if empty spaces lie beyond.

Since it is a one-way road inside, you cannot reverse back, so therefore you will prefer to take one of the available spaces that you can see near the entrance instead of taking the chance of driving further into the car park (as you can't reverse if you don't find a space). As a consequence, all the spaces visible from the entrance are normally full.

So, you enter the car park, see all the visible spaces are full. What do you do? Well, it depends. If there are empty spaces further on, then clearly driving on and finding them is the obvious thing to do. But if there are no empty spaces further on (and this car park is often full), then clearly remaining at the entrance is the thing to do as then any exiting car will be visible to you on the road ahead and then you can nip up and take their space. If the car park is full and you start driving along the road inside, the first space to become available might be behind you and it's a one-way road so you can't go back.

But when you are at the entrance, you cannot tell if the car park as a whole is full or not. All you can tell is whether the area near the entrance is full or not (and as explained above, it will tend to fill first). So, what many people do is drive in, see that the area near the entrance is full, assume (or fear) this means the whole car park is full, and so wait at the entrance until they see a car beyond pull out and exit. Since it is one lane road, all the other cars waiting to enter are stuck behind this first car in a long queue mostly outside the car park. And because they are waiting queuing outside, these other cars naturally assume that the problem is that the car park is full and each car coming in must wait for a car to leave in order to get a park. Now the car at the entrance can see the huge queue building up behind them, so they decide that they won't take a chance on driving through the car park looking for a space because if there isn't one, they will be forced to exit and then drive back and join the long queue.

So, the result of all this that the car park will be often be fully parked up near the entrance but with lots of empty spaces further in, but because of the one-way system, each driver fears it is full and waits for a car to leave, banking up more cars behind, reinforcing the message that the car park is full. So, you have lots of empty parks inside while cars are queuing outside. And even if a driver in the queue believes there are empty spaces in the far end of the car park, they can't trust their judgement and drive through because they are stuck behind the drivers who fear the carpark is full. Frankly, this seems to be an excellent lesson in how NOT to run a car park.

Oh, and just for bonus points, the cars in the queue outside are unable to decide to give up waiting because traffic islands and garden beds prevent them from leaving the queue and driving off elsewhere.

So, it's an interesting example of how unique factors (the physical structure of the car park) completely messes up a simple solution.

Presumably the solution lies in counting the cars in and out of the car gate (e.g. with boom gates) so that the driver entering can be told if the car park as a whole is full (and so wait at the entrance for an exiting car) or not full (so drive on into the car park and take the first space).

The other solution is to catch public transport or ride a bike.