There are certain rules for parking spaces designated for the people with disabilities. These rules are designed to facilitate the people with physical challenges. These parking rules may vary slightly from place to place.

There are rules of enforcement as well as fines for those who violate these disabled parking rules. All businesses are required to set aside a parking space for the disabled people to increase their accessibility.
There should be at least one disabled parking space in a parking lot which accommodates about 25 spaces. As the parking area gets bigger, so does the number of disabled parking spaces. So in a parking area of 100 spaces, at least four parking spaces for the disabled should be reserved and for a 500 space parking lot, there should be at least nine disabled parking spaces. Roughly, it should be about 2 % of the total number of parking spaces.
Special care must be taken for the size of the disabled parking space as well. It should be at least 12 feet wide and the parking space should be next to a handicap accessible path leading to the building. There should be an access strip next to the parking space.
A single access strip can be shared among a couple of disabled parking spaces. The access strip should be painted with diagonal stripes for indicating that no parking is allowed here.
The disabled parking spaces have to be outlined with blue paint. These signs must be placed in front of the disabled parking spaces; either the "international symbol of accessibility," which shows a person sitting in a wheelchair or a blue sign prominently saying "parking by disabled permit only".
Disabled parking spaces have to be marked very clearly and have to show the international symbol of accessibility. This sign should be clearly visible from a distance and should be at least 60 inches above the ground.
Disabled people should make use of the placards properly displayed on their vehicles. They can hang it over the rear-view mirror. These placards can be issued on a doctor's recommendation. These placards show the ‘international symbol of accessibility’ as well as include any additional information like the expiration date etc. Moreover, the disabled people should request a license plate too which displays the ‘international symbol of accessibility’. These things will get them the privilege to park in the disabled parking space.
Only those people are allowed to benefit from the disabled parking and stand or park in that space that have either a disabled parking permit or have a disabled license plate on their vehicle.
Any violator who parks in these areas will be fined heavily. This fine applies to those drivers who even though have a disabled permit or license plate to drive a disabled passenger but they misuse it by taking advantage of the disabled parking spaces when the disabled person was not in the car when it was parked.
There are certain medical conditions, apart from being physically disabled and wheelchair-bound, which allows one to use a disabled parking space. The doctor will recommend issuing the privilege to them too. These people include someone who is unable to walk for 200 feet without resting; someone with a cardiac problem; someone who cannot walk without using crutches or a cane. Moreover, someone having a prosthetic limb or someone on oxygen has the right to these privileges too.