Corner workers, also known as Flaggers, F&C, or Marshals, give consistent information to drivers with flags and signals (see below); help drivers and others in an incident; and communicate information to the stewards who are in charge of the event and make decisions based on worker communications because, unlike oval track races, the officials usually cannot see what is happening, and therefore rely on the accuracy of the workers' reports to make correct decisions. In an on-track incident, the safety priority of the worker is first to himself; then to his fellow workers; and then to the competitors. The corner worker's safety procedure is to recognize the hazard, know what to do to eliminate it, and do it in time for the action to be effective.

Corner workers have a number of main functions:

1. During sessions with cars/bikes on track, corner workers will constantly asess the condition of the track surface for accumulation of debris and oil. They will keep Race Control / Event Organizers updated if track conditions begin to deteriorate, and will the appropriate flags signals to warn competitors of potential hazards.

2. Corner workers will also observe competitors on the track for driving behavior and mechanical condition of their vehicles, inform Control of any issues with same, and as necessary, document observations in writing.

3. If a car/bike crashes or stops for any reason in their area of responsibility, workers stationed before that incident will display warning flags to oncoming race traffic. The communications person for that station will inform Race Control of the incident. Other workers will respond as necessary to further assess the incident and determine if it can be handled locally, and to perform initial fire suppression if necessary. In a case of a simple pull-off due to mechanical breakdown, corner workers will usually try to move a vehicle to a safer location farther from the racing surface and preferably behind a wall or guard rail. In a cases of a simple spin or off-track slide where the car is still able to continue, workers will help guide the driver in safely re-entering racing traffic. In case of more severe incidents, crashes, or fire, corner workers will request additional assistance from fire/rescue, medical, towing, and/or track clean-up personnel and their equipment.

4. Between sessions, or occasionally even during sessions with cars/bikes still on track when instructed by Control, workers maintain a safe race surface by sweeping debris from the track and drying any oil or coolant that may be deposited on the track by a race car or motorcycle.