Where you already in the opposite lane (already crossed one)? If so you had entered the rode prior to him clearing the intersection. There is a nearby city (Peachtree City, GA) established completely around MUPS (over 70 miles). There are specific crossings that have stop signs for the MUP. As far as the one intersection questions you would have to reference the state DOT rules. A lot of states are banning entrances within X amount of feet of an intersetion to avoid a similar situation.