NFL Flight Paths

Every mile reported here is great-circle (haversine) air distance between stadium coordinates, totalled by walking each team's schedule in chronological order. Between any two away games — even back-to-back ones — the team is modeled as flying home and back out. NFL teams almost always return home immediately after a road game (own beds, training facility, normal practice routine). The one exception modeled here is when the home detour would add more than 1,500 mi versus going straight to the next venue — which captures rare patterns like a West Coast team playing back-to-back games in the Northeast, or a team staying in London for two consecutive International Series games. Totals are rounded to the nearest mile.

Distance formula

Haversine on a spherical Earth with R = 3958.8 mi, implemented in src/geo.js · greatCircleMiles:

a = sin²(Δφ/2) + cos(φ₁)·cos(φ₂)·sin²(Δλ/2)
c = 2·atan2(√a, √(1−a))
d = R·c

Using a sphere rather than the WGS-84 ellipsoid shifts a transatlantic distance by less than 0.3% — well below the precision of stadium coordinates.

Per-team accounting

For each team we sort that team's away and neutral-site legs by week and walk them in order, starting and ending at the home stadium:

• Every road trip begins and ends with a flight from / to the team's home stadium. Bye and home weeks anchor the team at home in between trips.
• Between two consecutive road weeks the team still flies home in between by default. If going home would add more than 1,500 mi compared to flying straight to the next venue, the team is modeled as staying on the road and going directly venue-to-venue — the cross-coast back-to-back and back-to-back London cases.
• Neutral-site / international games count for both participating teams — including the team listed as the home designate. The 49ers' Mexico City "home" game is the canonical example: SF still travels.

What gets totalled

League total miles sums all 32 teams across the full schedule. International miles sums only the great-circle distance to neutral overseas venues, counted once per traveling team. Per-team rows in the sidebar show each team's full-season miles and stack the international portion as a contrasting bar segment.

Arcs vs. totals

The arcs on the globe show each team's home → venue flights as independent visual tracks; they don't include return-home flights or the rare venue → venue legs. The numeric totals reflect the realistic chronological path instead, so summing arc lengths by eye will undercount a team's total miles.

What's not modelled

• We assume bye weeks are spent at home (typical, not universal).
• No driving or local transit — pure stadium-to-stadium air distance.
• Preseason and playoffs are excluded; regular-season only.

Where it lives in code

• src/geo.js — greatCircleMiles(latA, lonA, latB, lonB)
• src/schedule.js — buildTravelLegs(schedule), summariseByTeam(legs), and the internal computeSequentialMiles walk
• src/ui.js — formatMiles(miles)