Which situation requires extra caution at a highway-railroad crossing?

A highway-railroad crossing requires extra caution at a passive crossing because these types of crossings do not have lights or gates to indicate when a train is approaching. Unlike active crossings, which are equipped with warning signals, passive crossings only have road signs to alert drivers to the potential presence of trains. Therefore, approaching a passive crossing necessitates a heightened awareness of the surroundings, as drivers must rely on their own judgment and visibility to determine if it is safe to proceed. The absence of automatic warning devices makes it critical for drivers to pay extra attention and ensure the track is clear before crossing.

Other scenarios, while they may increase caution under certain circumstances, do not specifically highlight the inherent risks associated with passive crossings where the onus is solely on the driver to be vigilant.