Infraco performance on upgrades and renewals is measured in terms of asset capability, which is the best practical journey time that can be achieved from the rolling stock, signals and track assets. The best practical journey time is the average total journey time a customer will experience, including platform waiting time and "on the train" time from arrival to destination, expressed in minutes. Figure 2 illustrates the improvements to capability that the Infracos have contracted to deliver for passengers over the life of the PPPs. Most enhancements are expected to be delivered between 2007 and 2015.