Transportation in Pittsburgh celebrates the city's natural resources. Tourists and daily commuters have realistic and diverse options, and the latter are often surprised to find that commute times here are lower than in similar-sized cities. Construction of new highways is under way, but bridges and tunnels are still gateways into the city. The Port of Pittsburgh is the busiest inland port in the nation, and there are more pleasure boat owners per capita than anywhere in the country. Inclines are a great way to see the city during a mountain descent, while light-rail cars offer additional transport and are free within the downtown area. Pitt students, faculty, and staff get the added bonus of fare-free service on Port Authority busses, trolleys, and inclines. The Pittsburgh International Airport is just 15 miles from the city and was rated the top airport in the nation and third in the world by Conde Nast Traveler.