How a track like Texas Motor Speedway can be listed accurately at two different lengths

Is Texas Motor Speedway 1.44 miles long? 1.5? Based on your line, it could change from lap to lap. (Getty)
Is Texas Motor Speedway 1.44 miles long? 1.5? Based on your line, it could change from lap to lap. (Getty)

Is Texas Motor Speedway a 1.5-mile track? It depends on who you ask.

The track’s actual length was debated on Wednesday as IndyCar held an open test at the speedway in anticipation of its June race at Texas. Since 2001, IndyCar has  officially listed Texas as a 1.455-mile course and adjusted that to 1.44 miles in light of Texas’ recent repaving and reconfiguration efforts.

As IndyCar’s measurements were discussed on Twitter, TMS president Eddie Gossage went so far as to say that IndyCar would be correcting its “error” that Texas wasn’t a 1.5-mile track like it’s officially listed.


But IndyCar and Texas can both be right. Here’s why:

• Tracks themselves list the published distance for NASCAR races while NASCAR, for timing and scoring purposes, measures the distance of a track one lane — approximately 10 feet — from the outside wall. If you were to run an exact 1.5 mile lap around TMS, you’d need to stay that distance from the wall the entire length of the track. It’s also safe to presume the addition of SAFER barriers on outside retaining walls has changed the official length of tracks very slightly for NASCAR’s purposes but not enough to be significant.

• IndyCar measures track length a different way. It takes the onboard telemetry from its cars and calculates the distance of a track via the preferred racing groove. And this is where the phrase “the inside is the shortest way around the track” comes into play. Since the preferred groove at Texas is much closer to the white inside line at Texas than it is to the wall, the series’ calculations come up with a shorter track distance.

• It’s why IndyCar’s measurement changed slightly again this week. In addition to resurfacing the track, Texas also widened turns 1 and 2 from 60 feet to 80 feet. By widening out those two corners, Texas shortened the distance of the inside line at the track enough to merit a change in IndyCar’s official lap distance. For both NASCAR and IndyCar, a car’s average lap speed is calculated via the length of the official lap distance and the time in which the lap was run.

Here’s where it gets fun. Gossage tweeted after the test that IndyCar had corrected its “error” with a picture of the speeds from the test. You’ll note that it says “1.5-mile(s)” at the top right.


The speeds and times don’t match up to a 1.5-mile track. Scott Dixon’s average lap speed of 221.974 mph would take 24.33 seconds to cover 1.5 miles. You’ll notice that his lap time is listed at 23.35 on the sheet. Via the math, Dixon’s average speed (as well as everyone else’s) is still based off traveling a distance of 1.44 miles. IndyCar’s calculation didn’t change. And that’s OK. Both Texas and IndyCar can be correct.

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Nick Bromberg is the editor of Dr. Saturday and From the Marbles on Yahoo Sports. Have a tip? Email him at nickbromberg@yahoo.com or follow him on Twitter!

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