Lorraine Harrington is shy but cheerful by nature. Sometimes she closes her apartment door and keeps to herself. But she really loves putting on a big smile and hitting the town.That’s not always easy for the 67-year-old resident of Columbia House, a downtown senior-citizen apartment building owned and operated by the Vancouver Housing Authority. It’s even less easy for many of her friends, who aren’t as healthy and as mobile as she is.“I am lucky, so far. Most people here have medical problems,” she said. “A lot of them can’t go anywhere.”So Harrington, president of the Columbia House residents’ committee, is gushing with praise for a new transportation program masterminded by VHA and its AmeriCorps/VISTA volunteer, Adna Tanjo. So far, the shuttle program is limited to a farmers market trip every other Sunday morning, but Tanjo is hoping it’ll blossom next spring into a more frequent service with regular visits to grocery stores, doctor offices, community centers — and even charter outings to fun occasions like the Clark County Fair.Seven downtown senior-citizen buildings have signed on to a cooperative plan to use and support the service. In addition to three VHA properties — Columbia House, Van Vista Plaza and Vista Court Senior Apartments — there are four private partners, too. They are Smith Tower, Kirkland Union Plaza, Knights of Pythias and Lewis and Clark Plaza.That means a grand total of 770 residents and potential riders, Tanjo said. The program is dubbed “Plan 770.”Tanjo doesn’t want to displace C-Tran, the Human Services Council, or any other transit service that’s already shuttling senior citizens around downtown, she said. She just wants to fill in some of the blanks they’re missing. For example, she said, it takes a hurried transfer between C-Tran buses to get from the west side over to the Marshall and Luepke centers. That’s just not possible for a slow-moving senior in a wheelchair or walker.