Britain's rail network is in many ways the victim of its own success - one of the safest in Europe, with a doubling of passenger numbers since 1997. That success has brought its own challenges as capacity is stretched, and any solution to that cannot come at the expense of reliability or still less of safety. Royal assent for High Speed Two (HS2) is a step towards a long-term increase in capacity, but in the short and medium term the existing national network holds the key. Much is going on in that field too.

The transport secretary Chris Grayling's December 2016 announcement had two main themes: an emphasis on working together within the franchise model, through integrated operating teams covering both train services and infrastructure - a sensible move, however patchy the success of alliancing arrangements; and the establishment of East West Rail - continuing the integration theme, but a deliberate challenge to the status quo that could constitute one of the most fundamental structural changes to the system for some time.

The Digital Railway programme seeks enhanced capacity from existing assets, and a similar theme on delivery is emerging here. The early contractor involvement (ECI) report flagged a change to existing industry practices as a key element of improving delivery, replacing 'telling suppliers what is needed' with 'conversations about the issues', and engaging earlier with the supply chain. The UK should benefit from the fact that digital systems are already deployed elsewhere, so suppliers come with tested solutions, rather than prototypes.

National rail does need significant investment, which may well need to come from private sources. Both the Hansford Review and the East West Rail team are looking at this.

Design Build Finance Operate (DBFO) models are one option, but it will be important to ensure that the necessary funder-driven contractual controls do not result in the inflexibility that has dogged so many private finance initiative (PFI) projects in their operational stages, and that these complex contracts are only adopted on projects where the effort of managing them properly is justified by the project's scale.

Grayling rightly wants to avoid 'two separate teams waving contracts at each other' between infrastructure and operator - and external finance risks the same approach occurring.

The railway is complex. Like many lawyers in the industry, I see the consequences of fragmentation daily - the break-up of the British Transport Commission in the 1960s which split London Transport from British Railways, and the restructuring of the national network on privatisation in the 1990s. Relationships that were based on teamwork are now based on contract, with collaboration often replaced by division and delay.

Grayling accepts the Shaw Report's recommendation of deeper route devolution by Network Rail, and McNulty's findings on achieving value for money. Network Rail's Transformation Plan, "Delivering for our customers" aims for work approvals at local level, to speed up decisions and delivery, and working with train operators on shared objectives and incentives through a scorecard system. However, local solutions may differ, and Network Rail must take care not to allow diverse solutions to spread confusion - some will say that it is already hard enough to understand just how Network Rail works and who to speak to.

Government understands the railway is an economic driver rather than just a transport system, but the interaction between politics and railway planning remains difficult. Mussolini famously got the trains running on time, but he did not achieve that through parliamentary democracy.

Almost every point made in the Commons in response to Grayling's announcement was about passenger traffic. The public and press (although clamouring for clean air) do not readily see beyond the reliability and cost of the daily commute. Where the papers go, the politicians follow. The struggle to explain HS2 as a capacity enhancement project is a clear lesson.

Focus on passenger services, while ignoring provision for freight could cost the nation dearly, especially in a post-Brexit environment. A strong trading nation will need the best support it can get from an agile and effective freight system.

And Brexit looms, of course: the process will stretch the Civil Service and eat up parliamentary time. For this reason alone, it is perhaps reassuring that Grayling says he is not planning to change the fundamental regulatory structure.

Brexit will also bring direct challenges for the railway; in this global industry the falling pound inflates costs for Network Rail, and reduces the value of sterling earnings for foreign investors. The UK may become a less attractive market or European base; and there will be debate over the future of European-led elements of our regulatory system.

The last year has certainly been eventful, and there is much promise in current developments, but no one should underestimate the challenges.