Prospective mayoral candidate and London travel expert Christian Wolmar says new boss of Network Rail Sir Peter Hendy has a "big job" when it comes to running the UK rail authority.
Speaking in an exclusive interview with London Live, he claimed the Hendy's former job at Transport for London and his new job are vastly different when they come to the way they are run.
He said: "TFL has a big investment programme but Network Rail is probably twice the size, four or five billion pounds just on improvements."
He also says he thinks Network Rail has "lagged behind" in "planned progress" so Hendy would have to "try to sort it out very quickly".
While he did say the new boss of the rail authority would be good for the job, he critisised the work he had done with London's cyclists.
He said: "If I could pick a fault with him I don't think he's been as enthusiastic about the cycle programme".