Philly has this! Our newest highway - the blue route runs wide around the city and connects the turnpike to close to Delaware. It has a queue system which only

Philly has this! Our newest highway - the blue route runs wide around the city and connects the turnpike to close to Delaware. It has a queue system which only let's on X cars per minute, preventing a heavy merge area from slowing everything down. Basically it's a stop sign with a red light at the on ramp. It goes green for a second, two cars go, it goes red. Interesting concept. More recently 76 has implenented variable speed limits to prevent backups - though it's entirely ignored unfortunately - you can't safely follow a 30mph limit when everyone is going 65 speeding their way into a jam