6. Bristol Airport, England ($4,400)
Bristol Airport is one of the busiest in the UK in terms of traffic. The airport serves as the hub for BMI Regional Airlines, EasyJet, and Ryanair. Before 2010, you had to take a bus or walk from the pre-boarding areas to the aircraft since they were parked on the apron. However, with the installation of a walkway in 2010, you no longer needed a bus.