One thing I've noticed in years of working on major infrastructure projects is that, there is no agency in goverment charged with anticipating future needs and implementing it. It's at a parochial level and we are always playing catch-up.
So we get a major project, possibly out in the sticks where, during the construction period, a large workforce burdens itself upon the local roads, doctors, dentists, hospitals usw. All the daily labour force and material deliveries come via county lanes.
Only when the job is finished does the local council kick into action and start to rebuild the roads, say. The process is so slow. Thus the big return on the investment is never realised. The other services are overburdened and some reluctant to treat. But they recover eventually.
I've tackled my MP about this but all he's interested in, is the local car factory..........
In the case in point, HS1 originally, was a child of the Thatcher era and have no public money. It was John Prescott who had to pick up the strands after Bechtel (L&CR) realised the sums didn't add up and wanted out. The £90m or so subvention to keep the project on track was 'justified' by the improvement to north Kent domestic services that became part of the deal. Thus his horizon was limited (beyond two Jags) to settling the immediate fudge and getting the project going again. Did he even think beyond that? It was hide-bound by political dogma from start to finish.
"That's what you get when you leave it to the politicians". Strategic thinking is done elsewhere. But not at all here, it seems.
As far as Arup is concerned, they are consulting engineers, and will do only what their remit requires. They don't get paid for 'extras'. So the strategic thinking and technical innovation has to be generated elsewhere. There's a yawning gap there somewhere.