Twice recently, I was in tight traffic and either saw lights or heard sirens behind me. Nobody was moving over and traffic was almost standstill. I pulled off the side of the road even though there wasn't any real shoulder. Then the other cars behind me, closer to the emergency vehicle, started to move over. I think it's dangerous that people got out of the habit of moving over. As an ex-EMT, I can't imagine how frustrating that must be for first responders.