requests bicycling directions via bicycle paths & preferred streets (where available).
(default) indicates standard driving directions using the road network.
requests directions via public transit routes (where available). If you set the mode to transit, you can optionally specify either a departure_time or an arrival_time. If neither time is specified, the departure_time defaults to now (that is, the departure time defaults to the current time). You can also optionally include a transit_mode and/or a transit_routing_preference.
requests walking directions via pedestrian paths & sidewalks (where available).
When you calculate directions, you may specify the transportation mode to use. By default, directions are calculated as
drivingdirections.Note: Both walking and bicycling directions may sometimes not include clear pedestrian or bicycling paths, so these directions will return warnings in the returned result which you must display to the user.