For Oregon - simply load City Navigator and switch on pedestrian option for navigation in device. No public transport but it is very quick on screen! For Nuvi 255 only same way as above is available. CityXplorer has not supported in both of your device. It is not so bad. You have Android tablet and easy to find the all public transport timetables. It is more actual and essential info by compare to CityXplorer. But for walking Garmin is the coolest!