HRS §291C-92
When you must stop at a railroad crossing
The state and counties can mark dangerous railroad crossings with stop signs. If you see one, you must stop close to the tracks and only go when no train is coming. If a train is near, wait until it passes.
The statute, as written — All vehicles must stop at certain railroad grade crossings
The director of transportation and the counties are authorized to designate particularly dangerous highway grade crossings of railroads and to erect stop signs thereat. When such stop signs are erected, the driver of any vehicle shall stop within fifty feet but not less than fifteen feet from the nearest rail of such railroad and shall proceed only if no train is approaching. If a train is approaching, and is approximately within fifteen hundred feet of the crossing, the driver must not proceed until after the train has passed.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.