Early buses were constructed without roofs but in more recent times they have only been built for tourist and sightseeing services.
Seasonal services are often in seaside towns, or along rural or coastal routes of particular scenic quality.
Open-top buses are often used for victory parades for sport teams, and as temporary viewing platforms at events such as The Derby.
Modern open top bus designs are available, nowadays with long multiple axle and low floor easy access features as seen on conventional closed-top buses.
Some open top buses have a re-fittable roof section, for fitting in inclement weather.