See also: Biking
Safe is a relative term; much depends on physical environment, and much depends on personal experience. Local bicycle advocates, such as the Washtenaw Biking and Walking Coalition and getDowntown, attempt to address both ends, by pursuing physical infrastructure improvements and educating cyclists (and motorists).
Cyclists debate riding in the street versus riding on the sidewalk; while the average 10-year-old or wobbly beginning cyclist is probably better off on the sidewalk, experienced cyclists, public works professionals, and numerous studies claim that the street is a much safer place for cyclists than the sidewalk. Streets typically have fewer obstacles for cyclists to run into (in central downtown regions such as Liberty, State Street, and Main Street, the sidewalk is particularly unsafe and impractical, due to the number of lampposts, sidewalk cafes, and pedestrians), and make it more likely that motorists will see the cyclists, reducing the chance for crashes at driveways or intersections.
The region's network of dedicated / designated bicycle facilities is patchy but growing, with initiatives such as the B2B Trail and the Ann Arbor 2007 Non-motorized Transportation Plan in place to work towards a more complete network. For example, Packard Street has a bike lane from its Main Street origin to Stadium Boulevard that allows cyclists to travel faster than motorists during rush hour traffic, but the bike lane simply ends at that point, dumping cyclists onto the four-lane segment of Packard. (A summer 2007 road reconstruction project is extending the Packard bike lanes several blocks past Stadium to a new sudden terminus.)
Off street riding
The parking lot at Burns Park Elementary is chained off on weekends, giving a nice expanse of asphalt for kids to ride around and around and around on.
There's a good sized bike trail that runs through Gallup Park.
On street riding
Iroquois Place has majestic speed humps that reduce traffic speeds to 5 mph, unless you are on a bike.