Double-decker bus
With the exception of coaches, double-decker buses are uncommon in the United States. Many private operators, such as Megabus, run by Coach USA, employs double-decker buses on its busier intercity routes.
Bus manufacturing
Operators may also make decisions on a particular bus type or components based on the particular terrain operated in. Some hillier areas may select different powertrain options. Areas with many low-bridges may have more single deckers than double deckers. Operators in humid climates may select air-conditioning as standard. A particular difficulty with double-deckers is trees striking the kerb-side top front corner. Manufacturers, or operators - post delivery, may fit a bull bar type arrangement to protect this part of the bodywork.