The 495 Express Lanes traffic studies done in 2004 by Vollmer (Stantec) and checked by Arup for lenders predicted peak trip time savings of 10-15 minutes for HOT-lane customers, who represented about a third of the drivers in the high-income corridor. Average trips on the 2×2 express lanes were predicted to be only a few exits so estimated time savings over the general purpose lanes were considerable.