Interestingly, they are increasing the speed on some of the northern bits of WCML through changing the bank of the track more. My understanding is that if the bank was too steep, slower running freight trains had issues with it even if faster running passenger trains were fine. With a general increase in the speed of freight trains, the speed differential is less so a higher bank can be tolerated, and I think there are sections of WCML where non-tilting trains can hit close to the speeds of the Pendolinos.