The Purpose of our research is to clarify how accessible parking spaces are installed and operated in the United States. We performed surveys of Washington DC(which is a special district controlled directly by the government), and the states of New York, California, and Hawaii Standards for installation locations, number of spaces, width and signage of accessible parking spaces are provided in the ADAAG (Accessibility Guidelines for Buildings and Facilities). Users of accessible parking spaces must display parking permits on their vehicles to indicate that they are entitled to use them. Those who park illegally without displaying a parking permit may have their disabled parking privileges revoked , have their car towed, be fined , or in cases of severe violations, be imprisoned . 1n every state we surveyed, accessible parking spaces were built based on ADAAG, so the parking spaces were easy to find. Furthermore, it was easy to determine whether or not vehicles were parked illegally by the presence or absence of a parking permit. For this reason, we were unable to find any illegally parked vehicles. 1n fact, with the exception of San Francisco, cases of accessible parking spaces being blocked by vehicles were rare. This was probably because sufficient spaces were prepared, so illegal parking is almost nonexistent. Japan does not have enough parking lots, so it would be difficult to increase the number of accessible parking spaces in the various parking lots. By preventing improper use of accessible parking spaces, the problem of people being unable to park may be mitigated. 1n future research, we shall consider effective methods of preventing improper use .