The tread depth requirement applies to which part of the tyre?

The tread depth requirement is crucial for ensuring adequate traction, handling, and safety while driving. It applies across the entire breadth and around the circumference of the tyre because a consistent tread depth helps maintain effective contact with the road surface. This ensures that the vehicle can perform optimally in various weather conditions, particularly in wet conditions where proper drainage is necessary to prevent hydroplaning.

Having the correct tread depth across the entire tyre allows for even wear, better stability, and improved braking performance. If tread depth is only measured on the outer edge or the inner tread, it might lead to misleading assessments of tyre performance and safety. Additionally, considering the spare tyre in regulations is important; however, tread requirements generally focus on actively used tyres to ensure overall vehicle safety.