Most low growing, mat-like groundcovers will take occasional but not constant foot traffic - the same dieback and "tracks" kids and dogs produce in your lawn will be duplicated in groundcovers. The only way around it is to use pavers, turf stone or other durable surface material in obvious pathways. Any living plant, even English ivy, will be damaged by constant foot traffic - "stepables" is only a marketing program, not a guarantee :-)

as gardengal suggested, pavers would be good, my neighbors have three young children and their walkway is lined with pavers and has "steppables" planted between each paver, looks really nice and becuase the pavers take most of the traffic the green in between is not compromised.
good luck