What is B grooves in aviation?

B grooves in aviation refer to a type of runway surface design that features transverse grooves or grooves that are perpendicular to the direction of the runway. These grooves are typically spaced a certain distance apart and are designed to improve drainage and reduce the risk of hydroplaning during wet or rainy conditions. The grooves help to channel water away from the surface of the runway, providing better traction for aircraft tires and improving overall safety during landing and takeoff.