Why do car tires have these patterns?

Why do car tires have these patterns? Wouldn't a smooth tire grip the road better? It sounds like more rubber should mean more grip. So why isn't every tire completely smooth? When the road is wet, a smooth tire can't move the water away. Instead, it slides on top of the water and loses grip. This is called hydroplaning. The patterns in the tire push the water out, so #car #cars #usa #shorts