Blair Gable / Reuters An argument broke out between passengers and the driver on a Greyhound bus after the driver reportedly showed signs of drowsiness, according to CBS-11. One passenger filmed part of the exchange. Greyhound eventually replaced the driver and got the passengers to their destination seven hours late. Staying awake is the most basic requirement any driver needs to meet, and passengers on a Greyhound bus traveling from Phoenix to Dallas on Thursday became concerned when their driver showed signs of drowsiness, according to CBS-11. "The bus was leaning little and that’s when people started to really worry," passenger Philip Hurd told CBS-11.