What is considered a safety hazard related to vehicle tires?

Insufficient tread depth on vehicle tires is considered a significant safety hazard because it directly impacts the vehicle's ability to maintain traction, particularly on wet or slippery surfaces. Tread depth is essential for channeling water away from the tire's contact surface, thus helping to prevent hydroplaning. A tire with inadequate tread depth can lead to reduced braking efficiency, longer stopping distances, and an increased risk of losing control of the vehicle.

While over-inflation can affect tire performance and durability, and punctures from nails can lead to tire failure, these issues do not universally apply to all vehicles and conditions as consistently as insufficient tread depth. Color discoloration is more of an aesthetic concern and does not influence the tire's performance or safety.