It’s not rocket science
Chancellor George Osborne “has asked @transportgovuk & @networkrail to develop biz case to get East Coast trains running at 140mph – cutting journey times”. Obviously, a much more sensible idea than building HS2.
But how could freight trains be pathed over a 140 mph passenger railway?
Probably, in much the same way they are pathed over a 125 mph railway (what the ECML is now) — i.e., with great inefficiency.
It’s not rocket science.
And of course, similar solutions are available for other corridors.