How fast does the average person walk during exercise?

Specific studies have found pedestrian walking speeds ranging from 4.11 to 4.33 feet per second (2.8 mph ~ 2.95 mph | 4.51 kph ~ 4.75 kph) for older individuals to 4.85 to 4.95 fps (3.3 mph ~ 3.38 mph | 5.32 kph ~ 5.43 kph) for younger individuals. from http://en.wikipedia.org/wiki/Walking