Downtown Calgary is home to one of the largest collection of corporate head offices in North America. One adaptation to winter is to create skybridges to connect offices, hotels, retail, cultural and convention centre buildings. Currently there are 63 bridges, connecting over 100 buildings, creating a maze that is over 20 km long. It is on par with Montreal's famous underground system. It is called the +15 system, as the skybridges are 15 feet off the ground, connecting buildings at the second floor level. The Core shopping centre which stretches over three blocks along Stephen Ave Walk pedestrian mall is connected by +15 and +30 bridges.

The original +15 bridges were simple rectangles without much thought given to the design; however they are gradually being retrofitted to become more visually appealing. One of the advantages of an elevated bridge walkway vs. underground is that pedestrians get to enjoy the sunlight and vistas the elevated glass bridges provide.