253.3 cm/s is the maximum men's walking gait, which probably looks something like this:

http://www.youtube.com/watch?v=2urNVmKnEaQ

For comfy gaits, the study reported 127.2 cm/s for women (2.8 mph) and 146.2 cm/s for men (3.2 mph). That matches my own experience walking and hiking.