11.A) Photo Speed Monitoring Devices in Public School Zones. The Board of Supervisors of the County of Frederick, Virginia will Hold a Public Hearing Regarding the Installation of Photo Speed Monitoring Devices by the Frederick County Sheriff’s Department, in Partnership with Blue Line Solutions (BLS), in Public School Zones within Frederick County, Virginia. The Purpose of the Photo Speed Monitoring Devices is for the Recording of Violations of Virginia Code § 46.2-873. Maximum Speed Limits at School Crossings.