Downtown Roanoke is small enough to walk in twenty minutes corner to corner, and the Hotel Roanoke Bridge connects the City Market to the railway station and Center in the Square as a continuous pedestrian zone. For everything beyond downtown, a car is by far the easiest option — the city has a public bus system (Valley Metro), but services run to suburban schedules and connections between attractions are awkward.
Roanoke Star, Mill Mountain Zoo, McAfee Knob and the Blue Ridge Parkway all need a vehicle. The Greenway trail system — the Roanoke River Greenway and Mill Mountain Greenway in particular — is good for cycling and runs from downtown directly to the start of the Mill Mountain Star Trail. Most car rental at the airport.