How must you act in this situation where the light and sound signals have come on at a railway crossing, but the gates have not yet begun to lower?

1. 1Proceed through the railway crossing.
2. 2Stop at the designated location, since proceeding through the crossing under these conditions is prohibited.
3. 3Stop only if the barriers have begun to lower.
4. 4Proceed through the railway crossing after making sure that no train is approaching it.