Skyway

A skyway, skybridge, skywalk, or sky walkway is an elevated type of pedway connecting two or more buildings in an urban area, or connecting elevated points within mountainous recreational zones. Urban skyways very often take the form of enclosed or covered footbridges that protect pedestrians from the weather. Open-top modern skyways in mountains now often have glass bottoms. Sometimes enclosed urban skywalks are made almost totally from glass, including ceilings, walls and floors. Also, some urban skyways function strictly as linear parks designed for walking.

In North America skyways are usually owned by businesses, and are therefore not public spaces as compared with sidewalks. However, in Asia, such as Bangkok's and Hong Kong's skywalks, they are built and owned separately by the city government, connecting between privately run rail stations or other transport with their own footbridges, and run many kilometers. Skyways usually connect on the first few floors above the ground-level floor, though they are sometimes much higher, as in the Petronas Towers. The space in the buildings connected by skyways is often devoted to retail business, so areas around the skyway may operate as a shopping mall. Non-commercial areas with closely associated buildings, such as university campuses, can often have skyways and/or tunnels connecting buildings.

The world's largest discontinuous skyway network – Calgary, Alberta, Canada's "+15 Walkway" system – has a total length of 16 km (9.9 mi). The Minneapolis Skyway System is the world's largest continuous system and spans 9.5 miles (15.3 km) connecting 80 blocks in downtown Minneapolis, Minnesota, United States.

On a smaller scale, terminals of large airports are often connected by skywalk systems, as at Manchester Airport, United Kingdom; in many airports, retractable jet bridges provide a direct connection between airplanes and terminals.

Some cities have the equivalent of a skyway underground, and there are also mixed subway–skyway systems; see underground city.

Besides pedestrian safety and convenience, the chief reasons assigned by urban planners for skywalk development are decrease of traffic congestion, reduction in vehicular air pollution and separation of people from vehicular noise. A number of cities (for example, Spokane, Washington) have given intricate analysis to skywalk systems employing computer models to optimize skywalk layout.

There is debate about the negative impact on urban areas of skyways. Robertson (1988) noted the negative impacts to street activities, and reductions to the property value at ground level. Woo (2012) found that skywalk systems could be negatively associated with promoting consumerism. Cui (2015) called for more research into the impact of skyways in developing countries. The Cincinnati Skywalk in Ohio was dismantled because of these concerns.

There are significant skyway networks in many cities in the US Midwest, such as Minneapolis, Saint Paul, Des Moines, Cedar Rapids, Rochester, and Duluth. Most networks in North America are privately owned. Notable exceptions are skyways in Saint Paul and in New York (High Line), which are publicly owned.