In my last post I commented on the potential of demand based road pricing and drew a comparison with the low cost airline pioneers of this. As Wired reports this is already reality. A section of Interstate 15 North of San Diego ( a busy section of road familar to me from trips to the ESRI UC) has a toll lane whose cost to use varies with traffic conditions. If it can happen in the wide open spaces of Southern California it can happen on the M25 !