By Guy Taylor Bringing more commercial freedom to the UK’s rail system will help bring down fares for passengers, the boss of Lumo and Hull trains has argued. Operator’s Lumo and Hull are one of a select few open-access train companies in the UK. The model means the companies take on full commercial risk while not being subject to hefty franchising fees. In an interview with City A.M., Martijn Gilbert said: “People are switching to us and that’s contributed to growth in the market and the open access rail model, you know, be it at Lumo, be it what our sister business has done at Hull trains. “…