Daytona: Speed and Secondary Accidents

We all know — and frequently remind ourselves — that racing will never be 100% safe. That doesn’t stop us from being stunned when it happens.

The 2020 Daytona 500

Let’s first give thanks for all the improvements NASCAR and their partners have made in safety at tracks, in cars and for drivers. While it’s hard to look at an accident that leaves a driver in serious condition as ‘good’, the alternative is far worse.

I don’t think I’ve made a secret of the fact that I don’t enjoy superspeedway racing all that much. I’ve been awed standing in the turns at Daytona and watched cars go past on banking so steep you can read the roof numbers. Daytona has history and tradition.

And yet, I don’t like watching things with my stomach clenched up waiting for the inevitable accident. Curiously, NASCAR didn’t call what happened on the last lap an ‘accident’. They list the cars involved as having finished running. The last thing I wanted to do this morning was re-watch the video video, but I needed to make sure that what I wanted to say was right.

Is Speed a Problem at Daytona?

Race cars and airplanes are both subject to the same physics. The former are designed to prevent lift, while the latter want to create lift. A lot is written about NASCAR racecars leaving the ground under certain conditions. Drivers — especially Ryan Newman — have been vociferous in their concern about that phenomenon.

“They can build safer racecars, they can build safer walls, but they can’t get their heads out of their asses far enough to keep them on the race track and that’s pretty disappointing, and I wanted to make sure I get that point across,” he said. “You all can figure out who ‘they’ is.”

Ryan Newman, Coming out of the Talladega Infield Care Center, 2013

NASCAR racecars leave the ground under a narrow set of circumstances. They won’t leave the ground at speed when going forward, but when they rotate, the aerodynamics are enough to cause the car to leave the ground. Cars can also get turns in collisions: we’ve seen them ‘launch’ off each other and go airborne, and we’ve seen cars get airborne by sliding into the track/infield boundary.

Newman’s accident wasn’t a simple case of ‘the cars are going too fast’. There was more to it than that. But the scariest part of this accident was not the first collision: it was what happened afterward.

Secondary Accidents

I’ve written before about secondary accidents, in which the car hits a wall or another car, but then engages in additional collisions. The worst of these is when a damaged car is hit by a car at speed that couldn’t stop in time.

The probability of secondary accidents goes up the more cars there are in your immediately vicinity. That’s why we rarely see ‘Big Ones’ at tracks other than where there is pack racing. Last night could’ve been much worse if the led cars hadn’t gotten out in front of the pack.

So the graph for today compares the numbers of cars involved in accidents at two big, fast tracks: Daytona and Michigan. Accidents are shown in blue and spins in orange. I realizes I named these graphs ‘multicar accidents’, even though I’m showing single-car accidents and spins. Oops.

And now the same for Michigan, on the same vertical scale so that you can compare.

It’s highly unusual at Michigan to see accidents involving over 4 cars. The most cars involved in accidents in the time period indicated is 9.

The average number of cars in an accident in the Daytona 500 is 4, and the most cars in a single accident in 1982-2020 is 21 cars.

The average number of cars in an accident at Michigan is 1.8. Neither number counts spins.

Newman’s collision wasn’t in ‘the Big One’, but accidents like his rarely happen at other tracks. Simple slowing down the cars won’t solve the problem.

It’s worth noting that no drivers were on track last night who had been on track in 2001, when Dale Earnhardt was killed. I hope this incident reminds everyone that even if the chance is small, you are never guaranteed to walk away from a racecar crash.

#RyanStrong