Waiting for the bus is easier with "real time" tracking.
Southern Maine Transit Tracker
This website has several tools to help plan and track transit trips in "real time" on METRO and regional partners - South Portland Bus Service and Casco Bay Lines.
All bus stops are listed on the Southern Maine Transit Tracker website
Download an app for your smart phone (Transit App, Moovit, are a few examples)
Text from the bus stop for the arrival time of the next bus.
All METRO bus stops have specific ID numbers.
To access arrival time via text -- (Stop#) to 4141
Plan your trip
Use Google Transit to plan your trip.
(Just click on the transit link)