There machinery and vehicles were still operational after Katrina. That makes a huge difference!
That was my point. That clean up is pretty difficult in a familiar disaster, much less one we aren't prepared for. That the depiction was realistic. I just think side streets would be relatively easy to clear. All the cars in the way would have been in drive when the electronics gave out. They could just be pushed aside to get at least one lane clear. That would probably have been a top priority for people who needed those streets.
But the population would be drastically lowered (but Jim wrote that part differently than I think would have been the case), so who knows if there would be people to clear the street? That's why I said it's the part I found least believable, not unbelievable. It's arguably how it would happen. I just don't think so.
The overall destruction of, and inability to replace, infrastructure is very believable. The degradation of infrastructure after the disaster is believable. The continued pile up of more garbage is believable. It took at least twelve months to clear the debris after Katrina.
I cite Katrina because it's the only example of a major disaster hitting a modern big city I have any familiarity with. And New Orleans is very small compared to Chicago.
