Fly under a bridge and it goes in your collection
Pilots have been flying under bridges since the photoreal world arrived, mostly because it is fun and a little stupid. Now it counts. 375 real bridges are on the list so far, from the Golden Gate and Tower Bridge to the Bosphorus and the long river crossings in Asia, and passing underneath any of them goes into your collection.
How a pass is checked. A bridge in map data is a line on the ground, so the line alone cannot tell under, over and through apart. The game asks the 3D city itself. The moment your path crosses a bridge's line, it looks straight up from the craft. There has to be a deck overhead, between 2 and 120 metres up, and it has to be thin: no more than 20 metres from its underside to its top, which rules out tunnels and overhanging cliffs. The same deck has to be there ten metres to either side along the bridge, which rules out a single tree or a lamp post. And there has to be air below you, so skimming the water through the mesh does not count either.
When the game says yes, the server checks your own recorded path crossed that same bridge in the last few seconds, at a height that fits. Then the bridge is yours.
Photoreal world only. The stylized map draws bridge decks flat at a guessed height. That is a picture, not a measurement, so bridges do not count there. Near a bridge in the stylized world the game tells you so, instead of leaving you to think something broke. Bridges in the New York mode do not count yet either.
Once per bridge. Each bridge counts one time for your account, for life. There are no tiers by day like the airports have. You get 25 XP for the bridge and a step on the Under the Deck achievement, which runs 1, 5, 15, 40 and 100 bridges, with 10 tridents at the top. Flying under a bridge you already have shows a small tick and nothing else.
Your bridges are listed under the airports on your My airports page: name, country, how much room you had under the deck, and the date. Guests can fly under a bridge too. Sign in within fifteen minutes and it is saved to your account.
When you get within 250 metres of a bridge on the list, a small note at the top of the screen names it, so you know it counts before you commit to the line.
Where the data comes from. The bridge list comes from Wikidata, which is public domain, picked by how many Wikipedia articles a bridge has. The deck lines come from OpenStreetMap: Bridge axes © OpenStreetMap contributors, under the ODbL. The 3D city is Google's photorealistic tiles.
Bridges are not on the map yet, and race gates under bridges are a separate idea we have not started. If a famous bridge is missing from the list, or one refuses to count no matter how cleanly you fly it, tell us in Discord with the bridge name and roughly where you passed.