Police are gearing up for traffic problems and rowdy fans when the New England Country Music Festival takes place at nearby Gillette Stadium this week. Last year’s festival led to terrible traffic backups in Walpole and problems with drunken concertgoers, according to Chief Richard Stillman. “They were drinking, urinating in yards and everywhere else. Fist fights broke out. It was just a mess,” he said. Police hope to curb those issues with a beefed-up police presence, starting on the roads before headliner Kenny Chesney takes the stage on Friday and Saturday evenings. Stillman urged residents to make alternative plans for getting around at those times “because there will be traffic problems, even if things go well. Avoid Route 1 at all costs,” he said.