Shapps does quite well in past comparisons of SoS. People forget about how bad Ruth Kelly and Geoff Hoon were (2007-8).
Rail policy is not just down to the SoS of course, his senior civil servants are key too.
Philip Rutnam was a high flyer at the Treasury before coming to Transport, then left for the Home Office and is now in ignominy after falling out big time with Priti Patel.
His time at Transport with Justine Greening and Patrick McLoughlin, which included taking financial control of Network Rail, was well regarded at the time for the huge investments they made during the Coalition in 2012 (HLOS/CP5), but most of which were ultimately undeliverable (for which the blame lies elsewhere).
Today's Permanent Secretary, Bernadette Kelly (ex Business Dept) is almost invisible, but is probably doing all the hard policy work on setting up GBR.