Ottawa has a bus service, a train, taxis, cycling paths and a lot of green space. For busses:
1-19: These are mainline or local routes that operate to/from or through downtown along major roads or in urban communities.
20-79: These are peak period routes connecting downtown Ottawa to suburban areas, running towards downtown in the morning and to the suburbs in the afternoon.
80-99: These busses run the transitway.
In general, the double-digit bus numbers go downtown. The three-digit busses go to the suburbs and farther distances from downtown such as Orleans and Kanata. (More info.)