Sir Richard C. Jebb, Commentary on Sophocles: Oedipus Tyrannus

[804-812] The κῆρυξ is, I think, identical with the ἡγεμών, and distinct from the τροχηλάτης. I understand the scene thus. Oedipus was coming down the steep narrow road when he met the herald （to be known for such by his stave, κηρύκειον） walking in front of the carriage （ἡγεμών）.The herald rudely bade him stand aside; and Laius, from the carriage, gave a like command. （With the imperfect ἠλαυνέτην, “were for driving,” πρὸς βίαν need not mean more than a threat or gesture.） The driver （τροχηλάτης）,who was walking at his horses “ heads up the hill, then did his lord's bidding by actually jostling the wayfarer （ἐκτρέποντα）. Oedipus, who had forborne to strike the sacred herald, now struck the driver; in another moment, while passing the carriage, he was himself struck on the head by Laius. He dashed Laius from the carriage; the herald, turning back, came to the rescue; and Oedipus slew Laius, herald, driver, and one of two servants who had been walking by or behind the carriage; the other servant （unperceived by Oedipus） escaped to Thebes with the news.