Section 3572 - Highway bridges on State highways(a) When it next becomes necessary to rebuild or reconstruct, in whole or in part, any existing bridge on a State highway that carries a public highway over railroad tracks, the State shall rebuild the bridge and pay one-half the cost thereof and the railroad corporation whose track travels under the bridge shall pay one-half the cost thereof; thereafter the State shall maintain, rebuild, and repair the bridge at its expense. If the rebuilding or reconstruction is made at the request of and for the benefit of the railroad, the railroad shall pay the entire cost. Maintenance, repair, and reconstruction or rebuilding, in whole or in part, required on bridges that were reconstructed or rebuilt in whole or in part for existing legal loads for State highways, subsequent to January 1, 1963, shall be made by the State at its expense.(b) Construction of new bridges carrying public highways over railroad tracks and rebuilding and reconstruction of existing bridges, when made necessary by reason of highway improvement incident to increased load, usage, or speed of motor vehicular traffic, shall be made by the State at its expense, except that to the extent any additions or improvements are made at the request of and for the benefit of the railroad, the added cost shall be paid by the railroad.