Using continuity notions for traffic

While I was waiting in the stand-still traffic on I-70 on my way back from Copper Mountain, it struck me that making sure highway traffic flows nicely is like the continuity equations in electromagnetics. And just like in a nice transmission line, one doesn't want abrupt changes in the highway. Unfortunately, that's not how they are built. If I-70 had been an entirely two lane highway from Denver to Silverthorne (where the traffic starts branching out), we would have nice a smooth conveyor of traffic. But we spent some unknown billion dollars building that third lane to the junction with US6, causing all the traffic problems along with it.