infrastructure. Windsor is connected to Essex and Leamington via Highway 3, and is well connected to the other municipalities and communities throughout Essex County via the county road network. Nearly 20,000 vehicles travel on Highway 3 in Essex County on a daily basis. It is the main route to work for many residents of Leamington, Kingsville and Essex. Windsor is linked to the United States by the Ambassador Bridge, the Detroit–Windsor Tunnel, a Canadian Pacific Railway tunnel, and the Detroit–Windsor Truck Ferry. The Ambassador Bridge is North America's No. 1 international border crossing in terms of goods volume: 27% of all trade between Canada and the United States crosses at the Ambassador Bridge. Windsor has a bike trail network including the (Riverfront Bike Trail, Ganatchio Bike Trail, and Little River Extension). They have become a blend of parkland and transportation, as people use the trails to commute to work or across downtown on their bicycles. Airports The city is served by Windsor International Airport, a regional airport with scheduled commuter air service by Air Canada Express, Porter Airlines, Westjet, and Sunwing, along with heavy general aviation traffic. The majority of destinations are within Ontario with the exception of seasonal routes to Calgary, Alberta and a variety of Caribbean destinations. The Detroit Metropolitan Wayne County Airport is approximately across the border in Romulus, Michigan and is the airport of choice for many Windsor residents as it has regular flights to a larger variety of destinations than Windsor Airport. Shuttle buses and cars are within driving distance to larger airports like London International Airport, John C. Munro Hamilton International Airport and to Canada's busiest airport and international hub Toronto Pearson International Airport. Waterways The Port of Windsor, which covers of shoreline along the Detroit River is part of the Great Lakes/Saint Lawrence Seaway System. Accessible to both Lake freighters and ocean-going vessels, the port is the third largest Canadian Great Lakes port in terms of shipments behind only Hamilton and Thunder Bay. Cargos include a wide range of products such as aggregates, salt, grain, fluorspar, lumber, steel, petroleum, vehicles and heavy lift equipment. Mass transit Road A public transport bus service is provided by Transit Windsor, the city-owned bus company, operating 15 fixed bus routes with a fleet of 114 vehicles through the city as well as providing transportation for many of the city's secondary school students and a service to downtown