Idea for air travel: Build platforms in front of every gate like they have for trains or rollercoasters. Plane pulls into the U-shaped dock/platform, opens on both sides like a Delorean, people with seats on the far side walk around the U to board at their row. Every row boards at once. When finished “doors” clasp shut. Figure it saves 10-20 minutes per flight for every traveler in perpetuity, vastly outweighing the cost of the platforms and re-design of the planes.