Two competing grocery stores have been creating traffic jams with an old-fashioned gas war and old-fashioned prices, as low as a dime a gallon.Kroger, the nation’s largest grocery chain, opened a new store Thursday, Nov. 29, about a quarter mile from a Meijer’s store. Both stores, as part of a growing trend toward one-stop shopping, have gas pumps outside.The price war began heating up within a few hours of the Kroger store’s opening. As soon as one station dropped its price, the other countered with a lower price.By 3 p.m., the price was 42 cents a gallon. By evening, gas was as low as 10 cents a gallon.“I’ve never seen people lined up to buy gas like this,” said Sandra Ralph, 60, of Dayton, in line at Meijer’s. “It’s a fantastic publicity stunt.”Gerald Harris, 25, and his brother Matt, 19, of Dayton, headed to Kroger.“You have to take advantage of it while you can,” Matt Harris said. “Gas may never be this cheap again.”Montgomery County Sheriff’s deputies kept an eye out to break up fights and try to maintain traffic flow.Brenda Bauer, manager of the Meijer station, estimated that more than 1,000 people bought the cheap fuel at the station.“The longer you wait in line, the cheaper the gas gets,” Bauer said. “There’s a deal there.”On Friday morning, Nov. 30, the price of gasoline at the Meijer was back up to $1.12 a gallon. But by noon, it was down to 71 cents a gallon, and it fell to 51 cents by early evening.