Some roads employ concrete switch ties in switches. Ties are made for that purpose and are made to the length of switch ties---the suckers are heavy!!. The ties are made to specifications such that anchors are cast in the proper places for switch frogs and/or movable points. Some roads don't use concrete for switch ties and instead use hardwood wood ties. I think some roads feel that wood ties in switches make the switches easier to maintain, especially when replacing parts, often parts such as frogs are "improved" or changed and the anchor locations cast into the concrete ties end up in the wrong location, a problem that is solved by simply drilling a new hole in a wood tie. Also roads have specifications as to gross ton miles of traffic and frequency of turn-out use that help determine if the great expense of concrete switch ties is worth it.