

I think you’re misrepresenting that a little. It’s not peer reviewed, doesn’t appear to have any researchers names attached at all, doesn’t mention latent demand, and doesn’t at any point consider that there could be other modes of transport. It reads to me like someone trying to sell their road building project.
Sort of, but but really. You’re right that historically the daylight hours set an upper limit on the amount of work that can be done per week for most types of work, but that limit is far higher than 8 hours per day over 5 days. The 40 hour work week is based on unions fighting for a 40 hour work week. If it wasn’t for the unions you’d be working all day every day except Sunday, for religious reasons.
That might change over the next few decades too, the current fight is for a 4 day work week and studies are showing promising results there.