José A. Alvarado Jr. Tamer Hassan is ready to get out of the street food game. He manages four food carts — smoothies, hot dogs, chicken and rice — on 49th Street, just off Times Square. At 45, he's been doing it for a decade. He loves the work, but is determined to leave the industry in the next five years, which means selling his business or convincing his son (an 18-year-old engineering student) to take over. The hours on his feet in all kinds of weather feel impossible to keep up with as he