Well, usually this is just a typo for smartpad. But that's not all...
SmartPed is a weight-sensitive pad designed to detect the presence of a pedestrian waiting to cross the street. Designed by Harding Traffic Systems, these are bight yellow squares which can be put in the place of concrete squares of pavement. When a pedestrian steps onto the pad, it sends a signal to the crossing signal.
There are all kinds of clever ifs, ands, and buts... For example, a pedestrian must stand on the pad for a certain amount of time before it will activate; otherwise any strolling pedestrian would set it off whether they wanted to cross the street or not. It is also "self-calibrating", in order to adjust for the weight of ice and snow.
The primary benefit over the more traditional crosswalk button is the easy activation for small children, the elderly, handicapped and visually impaired. But it's also cool to have the machines do all the work for us.