A two-driver crew departs Vienna for Rome at 06:00 on Monday. Driver 1 drives 4.5 hours while Driver 2 is on availability (Bereitschaft). After a 45-minute crew stop, Driver 2 drives 4.5 hours while Driver 1 is on availability. They repeat this cycle once more. At what time must the multi-manning shift end at the latest to comply with the 30-hour rule, and how many total driving hours did the crew accumulate?

1. Shift must end by 12:00 on Tuesday (30h window); total driving is 18 hours (9h per driver), leaving 9 hours for mandatory daily rest before 12:00
2. Shift must end by 20:00 on Monday; total driving is 9 hours combined
3. Shift can continue indefinitely because two drivers are on board
4. Shift must end by 06:00 on Tuesday; total driving is 24 hours