Traffic concerns topped Raynham selectmen’s list of potential problems from a casino being proposed for Taunton by the Mashpee Wampanoag Tribe. Selectmen recently forwarded their concerns to state officials as part of public comment on the project under the Massachusetts Environmental Policy Act. “Route 24 backs up now during rush hour, and that’s the proposed main avenue to the casino,’’ Town Administrator Randall Buckner said. “People cut through Raynham back roads to avoid the backup.’’ He said selectmen suggested the highway be expanded to three lanes in the area of the Route 140 exit. Selectmen also put anticipated increased mutual aid to Taunton, along with general increased pressure on the town’s public safety departments, on their list, Buckner said.