The Montgomery County Guide to Transportation Resources for People with Disabilities and Adults 50+ offers information on transportation options in the County and is available online at the URL link below. Senior SmarTrip cards may be purchased at any library in Montgomery County. To qualify, seniors must be 65 years or older, and proof of age is required at the time of purchase. One may also purchase cards at Division of Treasury, 27 Court House Square, Suite 200, Rockville; Monday through Friday from 8:00 AM to 4:30 PM.