Sound Transit Express ranks first in the nation in the number of commuter bus passengers carried and in vehicle miles driven.

[7] ST Express uses a flat fare system, where each ride costs the same regardless of distance.

The fares are as follows: Paper transfers are not accepted or issued on Sound Transit routes.

23 Sound Transit Express bus routes are overseen by the agency.

Sound Transit buses are painted white with aqua, turquoise, and blue waves along the sides, representing the Puget Sound region ST Express serves, and most feature a freely-adapted representation of the Sound Transit bus and train system map on the seating fabric.