The Better Business Bureau and the Franklin Police Department are warning residents about a springtime surge in asphalt paving scams.The scams often begin with a knock on the door and a high-pressure sales pitch. Scammers use different tactics, but a common one is to claim they have leftover material from a neighbor's driveway and they offer to do the work at 50% off.WATCH: How a Franklin Police dog is helping warn residents about a springtime s…