Under Department of Transportation (DOT) Americans with Disabilities Act (ADA) regulations at 49 C.F.R. Section 37.3, "service animal" is defined as "any guide dog, signal dog, or any other animal individually trained to work or perform tasks for an individual with a disability, including but not limited to, guiding individuals with impaired vision, alerting individuals with impaired hearing to intruders or sounds, providing minimal protection or rescue work, pulling a wheelchair, or fetching dropped items." DOT ADA regulation 49 C.F.R. Section 37.167(d) requires transit entities to permit service animals to accompany individuals with disabilities in vehicles and facilities.
Appendix D to section 37.167 contains further important information on service animals. It is important to note that while the U.S. Department of Justice has amended the definition of "service animal" for purposes of its ADA regulations under Title II and III of the ADA, for state and local governments and places that are open to the public, the definition under DOT ADA regulations for transportation has not changed. Therefore, members of the public may find that some service animals may no longer be considered service animals once they leave a transportation system.