Wisconsin Statutes Vehicles (Ch. 340 to 351) § 346.44. All vehicles to stop at signal indicating approach of train

(a) While any traffic officer or railroad employee signals to stop;

(b) While any warning device signals to stop, except that if the operator of the vehicle after stopping and investigating finds that no railroad train or railroad track equipment is approaching the operator may proceed.

(c) If any crossbuck sign specified under s. 192.29(5)(a) is maintained at the crossing, while any railroad train or railroad track equipment occupies the crossing or approaches so closely to the crossing as to constitute a hazard of collision.