Originally Posted by Epoch
I'm just pointing out that it's FEMA's responsibility to manage (It's where the M in FEMA comes from, in fact) responses across mutliple governments and governmental agencies. It's this broader level management that would make something like opening the other lanes possible. And if you open limited sections of the opposing lanes, you can nearly double the maximum throughput of the highway. OTOH, I'm armcharing and have never witnessed an incident where this was done.
Actually, I would submit that it doesn't change your throughput at all. Eventually, the south bound highway lanes need to switch back to the correct direction since there will be opposing traffic as you move farther north, and then guess what, you have to merge the people going north on the southbound lane back to the northbound lane, causing a jam. Ultimately, your throughput is exactly the same as having just the northbound lane. Also, if you jam up both sides, emergency services can't go into the city either.