Wheel–rail interface
The wheel–rail interface is the contact area where wheel–rail interaction between wheels and rails in railways takes place. This interaction is a specialist subject covering the design and management of the very high stresses in the small contact area between a steel wheel and steel rail. The focus is on safety improvement, maintenance and replacement costs reduction, downtime reduction, and energy and environmental management. The surface of the wheel that rests on the rail is known as the tread. Wheels can have either a single flange on the gauge side of the rail or two flanges, one on each side of the rail.
