Chicago's CTA has posted cab videos from the Red Line. They're time lapse, so are faster than "normal", but still interesting. Click on the picture to go to the Railway Age article, which has YouTube links.
Also, in most of the shots, including this one, there is what appears to be a fourth rail, where a narrow gauge third rail would be. It doesn't go through turnouts, and isn't the outside electric "third rail", so doesn't seem to serve any purpose. Does anyone here know what it's for? It's the rail just to the right of the coupler.
