Notice the little “channels” in the runway – the lines across it. These are “Grooves” & they help move water off the runway. Not all runways have them, but premium runways are both “grooved” & “crowned”….crowned means the center of the runway (width-wise) is slightly higher than the edges. In even heavy rain, the water flows off of it. My airline doesn’t give us a separate braking distance allowance for grooved & crowned, but we did take it into account on the KC-10. A grooved & crowned runway in the rain can have nearly the same braking action as a dry runway. The material used for the runway makes a difference, too, but at the airline they don’t bother differentiating. There aren’t many crushed coral runways left, but they were very good about draining water. In Vegas, you won’t find asphalt – with the heat & weight of the jet, it gets soft & we sink into it. The first 3,000’ of runways is generally concrete, and it’s much deeper than the rest of the runway, because it has to absorb the impact of landing. The rest of the runway can be less rugged. You’ll also see grooves on some highways. Same purpose, but I don’t think the highways are crowned.