This is rather interesting to say the least. I wonder how widespread the use of it will be though.
http://www.piercemfg.com/company/newsstory.cfm?ID=156
Here is one, that amtrak owns and it is in NYC, its the last picture on the page.
http://fdnytrucks.com/files/html/specialunits/otheragencies.htm
MP15NUT
I hope he gets track time before getting on the tracks.