I Couldn’t Find a Visual Racing Line of COTA Online, So I Built One

A free study map of Circuit of the Americas: the real track from a laser survey, an HPDE car's line coloured by throttle, coast and brake, and a how-to for every turn.

COTA, the whole lap, counter-clockwise. Green is throttle, amber is coast or partial throttle, red is braking.

This weekend, October 3–4, I'm back at COTA for the first time in three years, with Chin, in my son's Mach 1. The last time was April 2023, in my M5. Before I go, I want to study the shape of the line: where the car turns in, where it brakes, and where it goes flat.

I couldn't find it anywhere: the real track from above, with a real road-car lap on it. So we built it. It's live as the free Race Line pages on trackdays.ai, no login. Students can study it before an event. Experienced drivers and instructors can correct it.

What you're looking at

The grey picture is a laser survey, not a satellite photo. The USGS flies LiDAR over most of the country and publishes it for free; COTA's was flown in 2017. We grid it at half a metre and blend how brightly each spot reflected the laser (asphalt is dark, grass is light) with the shape of the ground. You see the kerbs, the run-off and the hills.

The line is colour-coded from the car's own speed trace:

• Green: throttle, including flat out on a straight.
• Amber: coast or partial.
• Red: braking harder than 3 m/s², about 0.3 g.
• White dots are apexes. Arrows show direction.
• A red-edged label is an off-camber corner, measured from the survey. At COTA: T4, T6 and the entry to T16.
• Dashed purple is a zone. At COTA it's the 103 dB sound limit.

Two sources: Formula 1's data and my own

Formula 1's data gives the track. We fitted Max Verstappen's 2025 US Grand Prix pole lap onto the map, to about ±10 metres. That gives a clean path around the circuit and the position of all 20 corners. It's the ruler.

My M5 gives the line, at 1 Hz. My 2023 logger recorded GPS once a second. I took my six fastest laps (2:41 to 2:43), filled in between the fixes using each fix's speed and heading, and measured each lap's offset from the F1 path every 5 metres. The line is the median of the six: my typical line, not one lucky lap. The line, the speeds and the braking zones are all the M5's. The six laps agree to about 1.3 metres, but I'd trust the line to about ±5.

Want to see it from the seat? Here's my M5 PB from that weekend, a 2:41.02.

How far to trust a line

Every Race Line page says at the top what its line is built from. Read it first. Where the line is my own laps, the chip shows the GPS rate. At 200 km/h, 1 Hz is a fix every 55 metres and 25 Hz every 2.2. So trust a 1 Hz line to about ±5 metres: the shape and the braking zones, not the exact metre. Trust a 25 Hz line to about a metre, close enough to see where the car sat on the road. COTA is one of only two 1 Hz lines left.

Where I don't have good laps of my own, the chip says Estimated. Those lines are estimated from data not in trackdays.ai: a typical quick HPDE line, not any one car's lap. Use them for the shape and roughly where the braking zones are, and take your exact markers from an instructor.

Why not just use the F1 lap?

My first version used the F1 lap for the line too. It looked great and taught the wrong thing. For T12, the M5 is on the brakes for about 280 metres. The F1 lap brakes for about 140, and starts 155 metres later. For an HPDE weekend, the M5 is the useful one.

T12, the biggest stop on the lap. Look how early the red starts. Start early, brake hard in a straight line, and pick a marker you can hit every lap. Move it only in small steps.

Corner by corner

Every corner on the COTA Race Line page has its own map and two or three sentences on how to drive it: braking, turn-in, apex, exit, and the one mistake to avoid. Here are the ones I'm studying hardest.

Sector 1. A steep uphill brake into the blind T1 hairpin, then downhill into the esses, where a tidy T3 is what makes T4 to T6 work. T7 to T9 climb back up and reward patience.

T1. Brake hard and straight up the hill, and finish most of it before the crest. The road crests just before the apex and the car goes light; the survey shows the crest clearly. The apex is hidden, so use a fixed brake marker and build up.

T11. A tight left hairpin onto the longest straight on the lap. Take a late apex so the wheel is straight early. This exit matters more than any entry.

Sector 3. T16 to T18 is one long multi-apex right: turn in once and hold a steady arc. T16 changes from off camber on entry to on camber on exit, so let the car load up before adding speed.

T20. A slow left onto the front straight: finish the turn before full throttle. The dashed purple line is COTA's 103 dB sound zone, enforced from T19 to start/finish, so short-shift through here.

How the notes were made

The notes are our own summary of 14 published guides, listed on the page: school and club guides, instructor notes, forums, pro walk-throughs and, last, sim guides. Where they disagreed, we started with the conservative HPDE version. Reader feedback has already changed that: T10 and the run through T3 are now drawn on throttle, and a pro driver's turn-by-turn guide added brake references for T11, T12 and T20. Every page now shows its version history and who helped.

Then every note was checked against the survey: every left and right, every "uphill", "crest" and "off camber". That caught four lines that put the car on the wrong side of the road, and one "downhill" that isn't there.

The survey can't check judgement: the marker you actually use, or where a student should lift. That's what instructors can add. Several tracks' turn numbers are provisional, too. At Barber the page uses JTI's numbers; Chin calls Charlotte's Web T5.

Three things I got wrong on the way

The colours. The first maps used blue for throttle and green for coasting, a colour-blind-safe palette rather than motorsport's. They read backwards. Now it's green, amber and red, with a brightness gap so colour-blind readers can tell green from red.

The direction. Our first COTA prep page said clockwise. COTA runs counter-clockwise: 11 lefts and 9 rights. I'd eyeballed it. Now direction is computed from the sign of the area the lap encloses, for every map and every corner.

The straights. The first rule called "not gaining speed" coasting. But flat out on a long straight, drag or a speed governor cancels the engine. My M440i holds about 209 km/h with the throttle pinned. So the straights showed amber where I was flat out. Now holding speed on a straight counts as throttle, with grade corrected from the LiDAR. A QA script checks every track for long "coasting" on straights, braking with no corner, and colours flickering back and forth. All 24 tracks pass, and a new track has to pass before it goes up.

The other tracks

Every Race Line on the Tracks page gets the same treatment. Each card says what its line is built from: my GPS rate, or Estimated.

• 25 Hz, my own laps. Road Atlanta: my best lap, a 1:40.17 in the '22 Z4 M40i on September 27, is the line. Same car, day and style as my Turn 7 crash: a fast line, not a safe one to copy blindly. Barber: my 1:45.99 in the '23 M440i. VIR Full: the median of six M440i laps.
• 1 Hz, my own laps. COTA, and FIRM (three of my M340i laps). I have nothing faster for either.
• Estimated. Roebling Road, Atlanta Motorsports Park, Sebring, Carolina Motorsports Park, Pitt Race, Mid-Ohio, Nelson Ledges, NCM Motorsports Park and VIR North, where my own laps were too coarse, plus ten new ones where I have few or no laps: Road America, Watkins Glen, Summit Point, Sonoma, Thunderhill East, the Daytona road course, the IMS road course, and Autobahn's Full, South and North courses. These are estimated from data not in trackdays.ai: a typical quick HPDE line, not any one car's lap. If you have laps at any of them, send them to upload@trackdays.ai and the estimate gets better.

Not possible yet: Ozark (the only survey predates the track) and Blackhawk (the survey covers under half the lap).

What's next, and what I need from you

This weekend I'll log COTA at 25 Hz in the Mach 1. That lap replaces the 1 Hz M5 line, and the page's rate chip changes with it.

If you have COTA laps at 10 Hz or better (RaceBox, AiM, VBOX, Garmin Catalyst, HLT, any 10–25 Hz logger), send them to upload@trackdays.ai and I'll rebuild the COTA line as a median of all of them: the more cars, the more honest the braking zones.

Instructors and experienced drivers: if a corner note says something you'd never tell a student, or misses what you always say, use the tell us link at the bottom of any Race Line page. We'll fix it.

The guides exist to help people. They're free for everyone. If your home track isn't on the list, say so; if you have 10 Hz laps there, better still.