What does this red-and-white crossbuck identify?

Correct answer: A place where a road crosses railway tracks

Why

The red-and-white crossbuck marks a railway crossing. Approach cautiously, look and listen for trains, and obey any gates, flashing lights or stop signs. Never enter unless the tracks and the space beyond them are clear. A separate number panel can indicate more than one track. This differs from the yellow railway warning sign placed in advance of the crossing; the PEI handbook teaches these signs for travel outside the province.

Verified against Prince Edward Island Driver's Handbook · Signs, Pavement Markings and Work Zones · p. 77, 78, 94