On railways, the layout of the tracks and number/length of platforms at stations will normally limit the extent to which a blend of fast/semi-fast/slow services can be operated.
In a typical metropolitan area limited-stop services are most likely to be scheduled at times when more people are travelling to and from their workplace. Leisure and shopping trips tend to be more localised and geographically varied, thus requiring and responding to slower services calling at most stops along the route.
In heavily congested traffic conditions a bus scheduled as fast or semi-fast may not always achieve an appreciably faster journey than a stopping service along the same route, unless there are special bus lanes.
Sometimes a higher (premium) fare may be required for the faster journey, especially for some international trains in western Europe.
Terminology for Dutch railways: