A tour bus service is an escorted tour (sometimes a package holiday) or bus service that takes visitors sightseeing, with routes around tourist attractions.
Double-decker buses and open top buses are commonly used, for providing a good view. Large coaches are used internationally by tour operators, intercity bus lines and charters, for short and long distance destinations. These buses are larger than regular transit buses, with 2 to 4 axles (6 to 10 wheels).
The history of tour buses in North America began in the early 20th century when trucks were converted to provide a means for sightseeing within large American cities. Gray Line, the largest sightseeing operators, began operations in 1910. Sightseeing was likely a side business for many intercity bus operators because the same types of buses were used (this remains true even today). World War II saw the industry decline, but it slowly re-emerged as an alternative to driving.
Many musicians, entertainers, dancing crews and bands travel in sleeper buses, commonly referred to as "tour buses". While most if not all of the buses and coaches listed above are for commercial applications, there are many coaches manufactured for personal use as motorhomes. These bus based motorhomes are considered the top end of the RV market.