Under what condition can a driver be given permission to cross a railroad track without stopping?

The correct answer is based on the understanding that crossing a railroad track requires careful consideration for safety. A driver can be given permission to cross a railroad track without stopping when the district transportation director is absolutely certain that the track is not in use. This guarantees that there is no immediate danger of oncoming trains, which is critical for ensuring the safety of both the driver and any passengers on the bus.

The other options may seem reasonable, but they do not provide the same level of assurance. Simply having the track clear or knowing the distance of a train does not necessarily mean it is safe to cross. For example, a train can travel quickly and may not be visible until it is too close. Additionally, just because the lights are not flashing does not guarantee that a train is not approaching, as the lights may not be operational or could malfunction. Therefore, the utmost authority and certainty provided by the district transportation director is what makes this option the safest and most responsible choice for crossing a railroad track.