NASCAR’s Penalty Box: Uncontrolled Tires

NASCAR changed the ‘arms-length uncontrolled-tire penalty’ after pressure from fans and drivers who complained that the rule was too subjective. Does the new rule solve those penalty problems?

Denny Hamlin tweet in response to his fifth Uncontrolled Tire Penalty of the season in Chicago

Does NASCAR Need an Uncontrolled Tire Rule?

A wheel/tire combination weighs around 70 lbs. A 3200-lb car at a pit road speed of 55 mph can smack into a loose wheel and give it enough momentum to send it flying toward pit road or the grandstands.

A tire (and other car parts) killed three race fans at a Michigan CART race in 1998 . NASCAR had its own close call at Daytona in 2015 when a crash sent car parts — including a wheel/tire — into the grandstands, injuring five spectators.

If you speed through the pits under green, you get a pass through penalty. The consequences of the violation aren’t all that serious. The possible consequences of a loose tire on pit road requires a rule that does more than discourage the behavior. It’s like drunk driving. You are arrested if you are caught driving drunk — even if you haven’t caused an accident or hurt anyone.

Unlike drunk driving, where there is a breathalyzer or blood test and you can quantify the magnitude of the violation, whether a tire is ‘under control’ is necessarily a little more complicated.

In 2018, NASCAR reduced the over-the-wall pit crew from six people to five as part of an attempt to cut costs. They also defined a tire as “controlled” when:

  • A crew member remains within arm’s reach of the tire
  • and is moving in the same direction as the tire when removed from the outside half of the pit box.
  • and the tire cannot roll into an adjacent competitor’s pit box 

Did The Uncontrolled Tire Rule Increase Penalties?

The pit crew’s goal was to achieve a pit stop in the same amount of time, with one fewer person. While pit times didn’t skyrocket, penalties sure did.

Pit Road penalties went from 277 in 2017 to 393 in 2018. If this year were to continue the way it's gone so far, we would end up with about 387.

Pit Road penalties increased from 277 in 2017 to 393 in 2018. I arrived at the figure for 2019 by assuming the number of penalties would scale, which would predict about 387 penalties in 2019. I expect the number to be smaller given the recent rule change.

What Caused the Increase in Pit Road Penalties?

Here’s a pie chart that compares the different types of penalties in 2017 vs 2018.

The forest green wedge at 11-12 o’clock is ‘other’, which I lumped all categories that made up less than 1% of the cautions into.

It’s a bit busy: Just focus on the big slices. In particular, note that the two large blue slices represent speeding on Pit Road. They get smaller in 2018, but it’s not because speeding on Pit Road went down. It actually went up a little.

Speeding is a much smaller slice of the pie in 2018 because there were huge increases in other categories. Let’s focus on those penalties that make up the bulk of the numbers. The blue bars below represent 2017 and the green bars represent 2018.

This bar graph compares the types of Pit Road penalties in 2017 vs 2018

There were some small decreases

  • Too fast exiting (63 vs. 68) Down 5
  • Safety violations (2 vs. 10) Down 8
  • Driving through 3 or more pit boxes violations (3 vs 12) Down 9

And there were some small increases

  • Disobeying a NASCAR request (13 vs 3) Up 10
  • Removing equipment (13 vs 3) Up 10
  • Too fast entering: (92 vs 82) Up 10

What Do Tire Violations and Too Many Men Over the Wall Have In Common?

The biggest increases in penalties came in two classes: Tire Violations and Too Many Men Over the Wall (TMMOTW)

Tire violations were up 53 and TMMOTW was up 34. Together, these two penalties accounted for 76% of the increase in 2018 over 2017: 87 out of 116 additional penalties.

Is There a Link between Too Many Men Over The Wall and Tire Violations?

I think there is.

Too Many Men Over the Wall (TMMOTW) seems like an easy violation to avoid, right? Aside from brain farts, the most common situation in which you see this penalty is when a car’s been in an accident. The crew chief sends more people over the wall to get the repair done faster. They will have an advantage, even with the penalty.

But a number of those ‘TMMOTW’ penalties recently were due to people behind the wall trying to corral tires and accidentally getting too much of themselves over the wall.

Why Was Hamlin the One to Complain?

Denny Hamlin is the driver most affected by the increase in Pit Road penalties. Hamlin ranks second in total penalties for 2019 with 10 penalties.

To illustrate that, I’ve called out tire violations in bright red and too many men over the in bright green in the chart below.

Although Corey Lajoie has the largest number of penalties, 7 of the 12 are from speeding on pit road and 3 are having pit crew members over the wall too soon. Their team only had one tire violation.

Hamlin ties with Ross Chastain for the largest number of tire violations att five.

Hamlin ties for 2nd with four others in Too Many Men Over The Wall.

Denny Hamlin has 10 Pit Road Penalties this year. (Experience has little correlation with a driver’s penalty rate.)

  • Uncontrolled Tires account for 5/10 penalties or 50%
  • Too Many Men Over the Wall accounts for 2/10 or 20%

In other words, 70% of the penalties the 11 team has received this year could be attributable to the uncontrolled tire rule.

Is the Problem the Rule? Or the Enforcement?


The popular argument is that the term ‘arm’s reach’ is simply too subjective.

nascarcasm's photo of an 18 pit crew member with an extremely long arm.

Denny Hamlin made the argument on Twitter that NASCAR shouldn’t have rules the average fan can’t explain.

If they don’t get it at home, then it’s probably not a rule that needs to be in place in the Cup series because you can’t explain it to them.

Denny Hamlin via NBC Sports

Plenty of evidence supports the assertion of missed calls. The photo at left, below, shows an uncontrolled tire call for the 12 car. The photo on the right shows a tire in a potentially more dangerous position, but the 4 car was not penalized.

NASCAR admitted they missed the call on the 4 car and a lot of people chalk that up to an inconsistent interpretation of the rules. But I think the problem is actually a little more subtle than that.

The Perils of Automation

The problem is inherent in the automated officiating system — which is used only at Cup tracks. Instead of having officials in pit boxes (which poses its own dangers), NASCAR now uses a system of cameras and software that incorporates laser measurements of Pit Road.

The computer system flags anything suspicious; such as something moving that shouldn’t be, or things that cross the pit box dividing line. But the computer doesn’t call the penalty, it only flags the stop.

Humans review flagged stops, but humans do not review all pit stops.

The Hamlin camp presented multiple videos of pit stops with “more egregious” tire violations than the ones Hamlin was cited for. They argue that the tire violation penalty was called incidentally when a stop was flagged for another reason.

What Hamlin’s team is claiming (and I think it was a much better argument than ‘fans don’t understand it’) is that the computer system doesn’t catch all the tire violations. They claim the computer is flagging their pit stops for some other reason and it’s only then that an inspector sees — and calls — the tire violation penalty.

NASCAR Listened

Honestly, this wouldn’t have happened ten years ago. Hamlin, although upset, had a rational argument against the system. There was plentiful video evidence. Kudos to NASCAR for listening and understanding the complaint. (And big kudos to Hamlin’s team for making such a strong argument).

Hamlin showed a problem with the rule and NASCAR changed it. So the problem is over, right?

So The Problem is Over. Right?

NASCAR’s fix addresses one of the two main problems with the rule: Requiring the tire to be within an arm’s length isn’t bad because it’s vague. It’s bad because it is too broad. If a tire is lying flat near the pit wall, with no one around it, it’s not as much of a safety hazard as one that’s just beyond an arm’s length in front of a speeding car.

After discussions internally and with competitors and teams, NASCAR will adjust how we officiate the uncontrolled tire rule to focus on preventing a safety hazard rather than concentrating on the subjective “arm’s length” criteria

Elton Sawyer, NASCAR vice president of officiating and technical inspection

The new language defines a controlled tire more specifically:

  • Safety issues include (but are not limited to) tires rolling into the traffic lane of pit road.
  • Tires may not be bounced or thrown at any time.
  • Tires may be rolled from the outside half of the pit box to the pit wall, providing they do not create a safety issue or interfere/impede another competitor’s pit stop.
  • Once tires are returned to the inside half of the pit box they may not roll back to the outside half of the pit box.
  • Tires, servicing equipment and crew members may not interfere or impede with another team’s pit stop. Tires contacting a vehicle while being carried to the outside half of the pit box may be considered a no call.
  • The penalty for an uncontrolled tire under green flag conditions will be a pass through, and starting at the tail end of the field under caution conditions.
  • Removed tire(s) from the outside half (race-track side) of the pit box must not exceed the “proximity limits” to other pit boxes as noted in the NASCAR Rule Book.
NASCAR's diagram, showing where tires may be without earning a penalty.

Isn’t This Still Subjective?

Yes. Some aspects are very clear. (No bouncing or throwing tires.)

Others are still subject to some interpretation. NASCAR acknowledges that tires in the traffic lanes are a safety issue, but reserves the right to penalize for other, unspecified safety issues. The question of whether an action impeded someone else’s stop is subjective.

NASCAR rules are always going to have some element of subjectivity. In this case, NASCAR rid themselves of a rule that was overly specific and very difficult to police equally given the current officiating system. While there is still the possibility that tire violations will be missed, it is now a much smaller possibility.


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