Why doesn't NASCAR race in the rain?

How Wet Track Conditions Affect Drivers
Crew members cover up tires during a NASCAR rain delay. Rain poses several major safety risks to drivers.
Crew members cover up tires during a NASCAR rain delay. Rain poses several major safety risks to drivers.
Christian Peterson/­Getty Images Sport

­Each NASCAR track poses its own benefits and drawbacks. All of those drawbacks intensify in wet weather. When rain starts falling from the sky, even a light drizzle, the caution flag goes up, but the red flag usually follows, signaling drivers to pull into the pits. Why not keep racing? All the fans are there, the crew is geared up, and the driver's already been racing and may even be ahead. Some people debate whether race organizers should let the race continue, but it all comes down to safety.

Each NASCAR track is built differently, but for the most part they all respond to rain the same way. If there is just a little moisture on the track, it's possible that NASCAR will bring out jet blowers to dry off the track and try to get the race started again. However, when there is a substantial amount of rain, it's much more difficult to get a track ready again. When it rains on a NASCAR track, the water starts seeping into the track. If it continues to rain, the water eventually builds up under the top layer of asphalt and looks for a way out. As the water increases, it starts flowing out of seams in the track. These streams of water are called weepers.

­These weepers pose a major risk to drivers as the car runs through them. To combat these unwanted streams, NASCAR will occasionally use saws to cut grooves into the track to allow the water to flow out of the track more quickly. This reduces the amount of water seepage and can help drain the track.

Even if these grooves are cut into the track, the lack of proper drainage onto the infield poses another risk. Drivers occasionally skid out and end up in the infield, where they can recover and get back into the race. In dry conditions, a driver may be able to maneuver his or her car out of the spin easily and get back into the race, but if that grass is wet, the driver's more likely to get stuck and have a difficult time getting back into place.

So, not only is it safer for drivers not to race in the rain, it also keeps them from losing position if their car is affected by the conditions. On the next page, we'll learn what goes into the decision to cancel a race, what happens to ticket holders when that happens, and how this affects NASCAR's bottom line.