For many years, bus and coach operators have experimented with vehicle types to find the vehicles that best fit their requirements. By borrowing buses and coaches from manufacturers and other operators, they can assess the pros and cons of new and existing examples of chassis and bodywork, try out hybrid and electric technology, experiment with features such as electric mirrors, or consider the use of fully autonomous vehicles. Such trials often result in large orders. Here, Richard Walter has selected a wide range of photographs from the recent past with a few older examples included as well. These reveal the types that were popular, the ones that were adapted and developed, and some that never saw the light of day. There are also examples of unique one-off vehicles that were subsequently bought and put into service.