The Americans with Disabilities Act ensures that all citizens can access business premises and public places by using their mobility aid of choice.
Segway Personal Transporters (PTs) are specifically identified as a device that provides exceptional mobility assistance for many individuals in the explanatory document ADA Requirements: Wheelchairs, Mobility Aids and Other PowerDriven Mobility Devices.
According to the ADA:
"People with disabilities have the right to choose whatever mobility device best suits their needs. For example, someone may choose to use a manual wheelchair rather than a power wheelchair because it enables her to maintain her upper body strength. Similarly, someone who is able to stand may choose to use a Segway® rather than a manual wheelchair because of the health benefits gained by standing."
In most US states the Segway PT is classified as a Electric Personal Assistive Mobility Device (EPAMD) when used by anyone - whether disabled or not - while the ADA ensures mobility users have even greater rights nationwide.