At a drawbridge without a signal light or traffic control attendant at the gate, what does PennDOT say a school bus driver should do?

1. Stop at least 50 feet before the draw and cross in a gear that avoids shifting on the draw span
2. Proceed without stopping if no boat is visible
3. Stop with the front bumper on the draw span
4. Shift gears midway over the draw to test the transmission