The case for HS2 depends partly on the idea that time spent on the train is unproductive, so that if you can make the journey shorter there will be big productivity gains for the economy.What do the passengers think?
The government document setting out the cost/benefit analysis puts the value of that time saving at £7.3bn by 2043 - and that's just for the section running from London to Birmingham.
But when I got on a train at Birmingham International, I found plenty of passengers - in First Class at least - who appeared to disprove that theory.
With free wi-fi on the train, they were hunched over their laptops and smartphones, busy working rather than idling away the journey.
If the HS2 project does go ahead the journey to London will be cut to just 49 minutes by 2026.Personally, it strikes me as a grotesque waste of money. They should concentrate instead on getting our existing trains to run on time, and adding capacity so that people don't need to stand.
But the passengers I met did not seem too excited by that - Roisif Wilson, who spends some of the week shuttling between offices in Birmingham, was not convinced that the money would be well spent.
"We use the internet for conference calls anyway," she said. "We're living in a much more technological age and I think it would be good to invest in better wi-fi for more people. It's not a significant enough difference for the investment."
Here's the latest from Westminster's most promising MP:
The Transport Committee’s report into High Speed Rail was released today. You can find it here.
I voted against the report. In my view, it is too supportive of the present proposals.
In committee, a number of us brought forward and voted for amendments which would have softened the report substantially. Some of these were defeated by just one vote. Full details can be found in the formal minutes at the end of the first volume.