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Following another car costs lap time: the wake disrupts downforce and overheats the tyres. The dirty air cost leaderboard quantifies that loss in seconds for each driver in a race, accumulating a flat per-lap charge for every lap that followed a lap spent close behind another car. It turns “stuck in traffic” into a number you can rank.

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What it shows

Each driver carries three dirty-air figures:
  • Total cost (cumulative_dirty_air_tax_race_s): the race-end sum of the per-lap dirty-air charge. Drivers who spent more laps closely following another car accumulate a larger total.
  • Average per lap (dirty_air_tax_s): the mean charge over the driver’s scored laps. Every charged lap is charged the same amount, so this is the share of laps spent following times that amount. It does not measure how close the driver followed.
  • Taxed laps: the count of laps where any dirty-air tax was applied (dirty_air_tax_s > 0).
The charge comes from one coefficient shared by every circuit and every season: a single OLS slope of lap pace against the field on whether the previous lap was spent following. A lap counts as following when the median gap to the car ahead through the middle third of the lap was under 1.5 s. A lap is charged that coefficient if the previous lap in the same stint was following, and nothing otherwise. It is not a per-circuit estimate, and it is not a function of how close the car was.
The first lap of each stint and the lap after a safety car, VSC or red flag lap are never charged. Pit laps and neutralised laps are not scored.

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How to use it

  1. Select a race from the filter bar; the leaderboard loads.
  2. Sort by total cost to see who lost the most to traffic over the full race.
  3. Compare average per lap to see what share of each driver’s race was spent following. Because every charged lap costs the same, it cannot tell you who was in the worst air.
  4. Read taxed laps to size how much of the race each driver spent following.

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Reading the signal correctly

Dirty-air cost is largely a function of track position and car pace, not driver error a quick car stuck behind a slower one accrues a large penalty through no fault of the driver. Read it as “how much traffic shaped this race”, and pair it with the lap air map to see exactly when the driver was in disturbed air.
The charge is one pooled coefficient, not a direct aero measurement and not a per-circuit or per-season estimate. A lap spent following at a circuit where following is aerodynamically cheap is charged the same as one at a circuit where it is expensive, and measured season by season the cost of following was highest in 2018. Totals differ between drivers only through how many laps each spent following.

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Data source

The chart queries int_dirty_air_tax_component via DuckDB-Wasm in the browser, for a single race. This is a single-race view across 2018–2025 data. For the full model definition, see the int_dirty_air_tax_component reference.