unlike Line, Shuttle pick-up and drop-off locations are the same every day, and so are the prices (with prices between $3–4 per ride, Shuttle is Lyft’s most affordable service
instead of coming straight to your door, Shuttle picks you up at a safe, carefully selected spot nearby.
unlike a bus route, a Shuttle route is on-demand — it doesn’t happen unless a passenger requests it.
"Just like Line, Shuttle matches you up with other passengers going the same direction to create a high-occupancy ride for a lower price than riding alone"