With both cars, pick-up's and semi's routinely traveling our interstates from North to South and reverse I believe the debate of running a designated "snow tire" to be a non-issue. The exception would be a vehicle with studded tires in which case in the state of Pa. those tires had to be removed by April 1st, if my memory serves me right. Summer and winters tires not only have different thread/tread designs but different rates of Silica in their rubber compounds. That would have a direct impact on winter traction and tire life. Technically tires have to perform in all kinds of conditions, be it winter or summer. Most tires are embossed with Threat Wear, Temperature and Tractions Rating which give the consumer some idea of the tires overall performance That said, many tires carry a all-season rating....good performance summer or winter