Transportation: Assist with driver training, appraisals, and schedules, and ensure safety practices are followed.
Traffic control. Oversee road and highway construction projects, including using traffic control devices to direct drivers and pedestrians, and supervising equipment installation.
Highway maintenance: Oversee the maintenance of roadways, bridges, and structures, and develop program goals.
Street maintenance: Oversee day-to-day road maintenance activities, including resurfacing and patching roads. They may also participate in these tasks.

(In general, supervisors are responsible for managing workflow, training new hires, creating schedules, and evaluating employee performance. They also communicate organizational needs, provide guidance, and help resolve employee issues.)