Parking Meter

Usability Study

by Taylor Roan

Shortcomings

There are many issues regarding the usability of the current Cambridge parking meters. The main usability problems confront the Customer.

Unclear Payment Interface

When paying for metered parking, the customer merely needs to know how much parking costs and how to pay. As seen from the car, neither of these questions are even addressed. Take a look for yourself (below, left). When you get out of the car and go to the other side of the meter (below, right), you can finally glean a few hints on payment, but it is more like a scavenger hunt than walk in the park.

You can find the price hidden in the window in an area almost impossible to see due to glare (below, left). The money type is also nestled in there. If you had forgotten to bring quarters to the meter, you'd better go back to the car and get some. The coin slot is easy enough to find (below, right). There is also a card reader located next to the coin slot. But don't be fooled, it doesn't do anything.

Confusing Context

The one set of information that is visible from the street is the many signs that plague the sidewalk. What do you think that the sign below means regarding the adjacent metered parking space?

I guess that I can't park to the left of the sign ... but on the right? I can only park in two-hour increments from 8am to 6pm Monday through Saturday? What if I want to park for less? What happens during the night and on Sunday? No parking at all? No two-hour increments? Not too clear ... It's even more confusing since the exact same arrangement of signs can be found for unmetered parking.

This arrangement of signs actually means that you can't ever park to the left of the sign, but you can park to the right of the sign as long as it is not a snow emergency. You can only park there for up to two hours from 8am to 6pm on Monday through Saturday. You must pay to park during these times. At nights and all day Sunday, you can park as long as you like and for free. What? You didn't get that from the signs? Me neither.

Enigmatic Orientation

Imagine that you've just parked your car, and you see the meter shown below next to the front passenger corner of the parking space.

Which meter should you use - the one closest to your car, or the one facing your car? The correct answer is the meter closer to your vehicle. Had you never used a parking meter, the answer would certainly not be obvious. Even having used parking meters before, this ambiguous orientation can still be confusing.

Location Ambiguity

Meter location can also often confuse the customer or enforcing officer. Can you tell which car should use the meter below?

Some users claimed that one should always pay the meter in front of the space they park. However within the immediate vicinity there were counter-examples of single-headed parking meters which could only be associated with the car in from of them. Double meters are also an obvious contradiction to the "only-pay-the-meter-in-front-of-you" principle. Users have little choice but look down the street in both directions and calculate meter allocations for all of the parking spots until they can conclusively determine which meter to use. Such meter-mapping opaqueness is aggravating and a waste of time.

Color Inconsistency

As you drive down the street, you see the meters below.

What to the colors mean? Does red mean that parking in this spot is prohibited? Does yellow mean that you should exercise caution when parking here? Does green mean that it's okay to park here? It's not clear at all. Parking meters tend to mix color metaphors commonly used in traffic.

The intended meaning of the above meter colors for an open space is as follows. Green means that there is still time remaining on the meter, which means that you get a certain amount of free time if you choose to park there. Yellow means that the meter is broken and that you may park there for free. Red means that the parking meter is functioning, and while you may still park there, there is no free time remaining on the meter. Surprisingly, the red case is the expected functioning scenario for a person pulling into an available metered parking spot.

The color ambiguity is amplified by painted meters, such as the meter shown below. Does the yellow paint mean that this meter is always broken and free? I'm guessing not.

Part of the color ambiguity comes from the different scenarios of use. Take the current use for the red indicator for example. To the enforcing officer, this indicates that a car parked in the corresponding stall deserves a ticket. To the meter maintenance crew, red signifies that a meter is likely working properly. To a customer parked in the space, this color shows that their time has expired. To a customer looking for parking, red suggests that the space is available for parking if empty. It isn't difficult to see how one could mix color metaphors considering the many different viewpoints of parking meter users.

Cryptic Displays

The digital displays are also terribly puzzling. Can you tell what the following displays mean?

Let's start with the middle display, since it's probably the easiest. The positive numbers mean that the customer has parking time remaining. It's not obvious whether the customer has 55 seconds, 55 minutes, or 55 hours left at this point. The actual amount of remaining time is 55 minutes.

The display on the left shows a negative number. Does this mean the amount of time since the customer last paid? Does this mean the amount of time a customer must wait to park here? If a customer were to insert coins, would they have to pay enough to offset the negative value before they could purchase more time? Would a customer even notice the negative sign or be able to discern it from a dash? Dubious. This actually shows how long ago the meter payment expired.

The display on the right is actually meant to read, "JAM". In tiny letters along the top it also displays "OUT OF ORDER". While the meaning of this display is discernable, the implications of it are not. Can a customer still park here? Must they pay? What about the time limit? Your guess is as good as mine. This display is actually analogous to the yellow meter indicator color, meaning that parking is free within the posted time constraints.

Theft

Current meters have a mild tendency to be stolen. Last year, a Somerville resident stole over 75 parking meters from the City of Cambridge. He cut the heads off with a pipe saw, and left the meters lying next to the poles until a friend drove along the route and threw them in the back of his truck.

This isn't to day that meters fail in the theft prevention department. I also interviewed a man who stole a parking meter by smashing it repeatedly with a sledgehammer until the entire meter was dislodged from the sidewalk. After bringing the meter home with him, he spent hours drilling into the coin box until he was finally able to access the money. He was disappointed that he only received $30 for his effort. The low value to effort ratio of meter theft is actually a pretty good deterrent for repeated theft.