Flat Spots: Greater than 2 1/2 inches in length but less than 4 inches in length, how may you proceed?

• A. Proceed not exceeding 10 MPH and contact dispatcher
• B. Continue at Normal Speed
• C. Stop immediately
• D. Increase speed to 15 MPH

Answer: (A)

A wheel with a flat spot is a defect that changes how the car rides and can cause damage if you run fast. The length of the flat determines the safe speed. If the flat spot is between 2 1/2 inches and 4 inches, the proper procedure is to proceed at a restricted speed—not exceeding 10 mph—and contact the dispatcher. This gives you enough control to avoid excessive vibration or derailment risks while arranging an inspection or service for the wheel.

Continuing at normal speed would be unsafe because the defect can worsen and stress the suspension and rails. Stopping immediately is typically reserved for more severe or obvious faults, and increasing speed would worsen the issue. So the recommended action fits the level of the defect and keeps you under control while getting the wheel inspected.