A series of engagement events and workshops were also held across the UK over the past four months, to test and challenge some of the written submissions. Culminating at KPMG's London offices in Canada Square on 27 April, they also give attendees the opportunity to engage in the wider debate regarding delivery of infrastructure in the UK.
Over 400 organisations and individuals from across ICE's membership, industry, business, environment, economic and academic communities have engaged with and contributed evidence to the project, which aims to establish an independent evidence base on the UK's infrastructure needs up to 2050 and facilitate more strategic choices. 600 people from the wider built environment, legal, political and professional services, and members of the public, have also engaged and shared views via Twitter using #UKInfraNeeds.
The NNA is being chaired by ICE President Sir John Armitt and 11 other high profile organisations are part of the NNA's Executive Group - including CBI, KPMG, Pinsent Masons, University of Cambridge, University of Oxford, National Grid, London First, Green Alliance, Transport for Greater Manchester, Thames Water, the Scottish Council for Development and Industry and Graham Dalton, former Highways Agency CEO.
The Group's diverse networks were utilised to draw evidence from a broad base and widen the debate on future infrastructure needs.
Evidence gathered during the process is now being analysed. Academic research underway by Oxford University's Infrastructure Transitions Research Consortium will also form part of the evidence base, along with other economic and environmental data.
Speaking at the final evidence gathering conference in London, Sir John Armitt, said:
"The response has been huge, and has provided us with a wealth of evidence and expertise. I am delighted the NNA has been embraced in this way.
"I believe the collaborative nature of the project has played a part, creating real a sense of excitement. A group of very different organisations working together - ultimately to benefit society, grow the economy and drive the shift to a low carbon future.
"The approach feels fresh, like we have broken down the silo mentality for the common good. This has come across in all of the evidence gathering sessions.
"We have covered significant ground, and some themes have emerged – not least the interdependent and vulnerable nature of our infrastructure systems. The way the sectors interrelate is still largely misunderstood or unappreciated, and there are questions that keep coming up and need answering."
"I look forward to publishing our findings and conclusions in the autumn, and sharing our work with the National Infrastructure Commission." he added.