Streetsblog USA via California Rail News

Speed. Routes should be direct, instead of cutting labyrinthine paths across a city. Fare payment needs to be fast and easy, via off-board fare collection or tap-and-go entry at every door. Transit can’t get bogged down in traffic, either, so features like dedicated space on the street and priority at traffic lights are needed to keep things moving.
Frequency and Reliability. People won’t ride transit if they can’t depend on it…
Walkability and Accessibility. Transit works best when people can walk to it. That means both concentrating transit in compact, walkable places, and making it easier to walk to transit in places where pedestrian infrastructure is lacking…
On the Dublin buses you can pay your fare with a tap card. Passengers can walk past the farebox next to the driver to tap the card reader and not wait behind cash paying riders to dig out their money.