That doesn’t mean it’s zero-sum: The existence of a handicapped parking spot that I can’t use might cost me an extra 20 seconds of walking, but save an extra five minutes of painful limping for the person who uses it.
This does not demonstrate that handicapped parking spots aren’t zero-sum (or, indeed, even that they’re not negative-sum). Merely comparing the advantage to one handicapped person of parking in a reserved spot, and the disadvantage to one non-handicapped person of having one less spot (in an optimal location) available, is not enough; you must multiply both quantities by the number of instances affected (respectively, the number of occasions on which a handicapped person uses one of the reserved spots, and the number of occasions on which a non-handicapped person uses one of the regular spots), and compare those quantities.
It is very, very easy for an accommodation like this to end up being negative-sum.
Or for past me, on a couple of occasions when I’ve been injured
To be able to use a handicapped parking space, it is not sufficient to be injured; one must also apply for a handicapped parking permit, which is not a trivial process.
I have, several times in the past, been injured in such a way that I would have benefited from being able to use a handicapped parking spot. On zero of those occasions was it even remotely practical to apply for, and receive, a permit that would enable me to do so. Because of this, while handicapped parking spaces could have helped me on a number of occasions, they have actually helped me never.
I agree that allocation is hard and in particular that if regulations overboard with trying to ensure that there will always be more handicapped spots than there are people who need them, there’s a point at which adding spots becomes net negative. As for the point about injuries, you’re right—I wasn’t thinking clearly there and it doesn’t apply, at least not in the current US implementation of handicapped parking.
I agree that allocation is hard and in particular that if regulations overboard with trying to ensure that there will always be more handicapped spots than there are people who need them, there’s a point at which adding spots becomes net negative.
Indeed. The difficult question, of course, is: what exactly constitutes “going overboard”, here? How often is it acceptable for a handicapped person to need a reserved parking spot, but not be able to get one (because they’re all full)? Whatever answer we come up with, I sure don’t envy the politician who has to defend that answer to the public!
But also, how would we come up with an answer? (Would we have to go all the way to fully general utilitarianism, where we calculate how many utils are lost by the average disabled person who has to park in a regular spot, and how many utils are lost by the average non-disabled person who has to park slightly further away due to the presence of empty reserved spots? How would we account for the effect of the presence and number of reserved spots on people’s behavior?)
How do these decisions actually get made? Like, in real life—how is it determined that there shall be this many handicapped spots in a shopping center parking lot?
In other words—you write:
Third, because if you’re a decision-maker of any kind, recognizing a handicapped parking situation means you have the opportunity to be conscious about allocation choices, or look for ways to make allocation smarter and more flexible.
Do you know of any resources that go into detail on this? Are there such?
I didn’t know much about this subject when I made the original post, because I was interested in handicapped parking as a design pattern rather than a specific topic, but it turns out that the ADA has a very clear answer: 2-4% of all spaces, with a minimum of 1 space.
I don’t know how they came up with that percentage or if there’s any mechanism for updating it based on the prevalence of mobility limitations. Requirements are considerably higher for hospitals and rehab facilities, which does seem sensible.
This is a topic I’d like to learn more about sometime. I imagine it causes some tension for urbanist types because they tend to love accessibility but hate parking space mandates.
This does not demonstrate that handicapped parking spots aren’t zero-sum (or, indeed, even that they’re not negative-sum). Merely comparing the advantage to one handicapped person of parking in a reserved spot, and the disadvantage to one non-handicapped person of having one less spot (in an optimal location) available, is not enough; you must multiply both quantities by the number of instances affected (respectively, the number of occasions on which a handicapped person uses one of the reserved spots, and the number of occasions on which a non-handicapped person uses one of the regular spots), and compare those quantities.
It is very, very easy for an accommodation like this to end up being negative-sum.
To be able to use a handicapped parking space, it is not sufficient to be injured; one must also apply for a handicapped parking permit, which is not a trivial process.
I have, several times in the past, been injured in such a way that I would have benefited from being able to use a handicapped parking spot. On zero of those occasions was it even remotely practical to apply for, and receive, a permit that would enable me to do so. Because of this, while handicapped parking spaces could have helped me on a number of occasions, they have actually helped me never.
I agree that allocation is hard and in particular that if regulations overboard with trying to ensure that there will always be more handicapped spots than there are people who need them, there’s a point at which adding spots becomes net negative. As for the point about injuries, you’re right—I wasn’t thinking clearly there and it doesn’t apply, at least not in the current US implementation of handicapped parking.
Indeed. The difficult question, of course, is: what exactly constitutes “going overboard”, here? How often is it acceptable for a handicapped person to need a reserved parking spot, but not be able to get one (because they’re all full)? Whatever answer we come up with, I sure don’t envy the politician who has to defend that answer to the public!
But also, how would we come up with an answer? (Would we have to go all the way to fully general utilitarianism, where we calculate how many utils are lost by the average disabled person who has to park in a regular spot, and how many utils are lost by the average non-disabled person who has to park slightly further away due to the presence of empty reserved spots? How would we account for the effect of the presence and number of reserved spots on people’s behavior?)
How do these decisions actually get made? Like, in real life—how is it determined that there shall be this many handicapped spots in a shopping center parking lot?
In other words—you write:
Do you know of any resources that go into detail on this? Are there such?
I didn’t know much about this subject when I made the original post, because I was interested in handicapped parking as a design pattern rather than a specific topic, but it turns out that the ADA has a very clear answer: 2-4% of all spaces, with a minimum of 1 space.
I don’t know how they came up with that percentage or if there’s any mechanism for updating it based on the prevalence of mobility limitations. Requirements are considerably higher for hospitals and rehab facilities, which does seem sensible.
This is a topic I’d like to learn more about sometime. I imagine it causes some tension for urbanist types because they tend to love accessibility but hate parking space mandates.