People are Walking Slower Now

In the WSJ,  studies indicate we walk slower now.  Implications for the modeling of retail spaces?

 " ... Pedestrians need more time, too. For years, traffic lights here and nationwide were timed to the stride of the average pedestrian, who covered 4 feet of ground per second, according to federal research carried out in the 1950s. A couple of years ago, however, the Federal Highway Administration urged traffic engineers to recalibrate to an average stride of 3.5 feet per second, after new research showed that Americans' average walking pace had slowed over the decades. That would give elderly walkers more time to cross safely ...  "