Electronic boarding gates
 

Most EU airports now have electronic gates that open and close after you scan the boarding pass. This allows for more people to board at one time, allows just a single agent to monitor 3-4 gates, and prevents people from skipping groups. Any idea why US airports don't implement a similar system for boarding? The boarding process in most US airports is very chaotic.

I assume the gates, like most things, cost money, and the airlines don't want to spend the money.

They have it at TBIT at LAX. I think they are called skylanes. You don't even need to scan your QR code on the boarding pass: just scanning your face. Because it is international terminal, they already have your face information from passport.

The new Terminal A at EWR has the e-gates and they seem hit or miss from my flights so far. I've discovered they are programmed to not allow use if seated in an exit row (annoying, but I understand) and they seem pretty glitchy from my last few trips through. BOS also has some, though I haven't used them yet.