I have a family member who was an engineer in the Federal Highway Administration for many years. The amount of waste and excess cost on these projects is really hard to exagerate.

Comparative costs to other OECD countries for similar infrastructure - there really isn't one, as the US is way out of line in terms of cost and quality.

My family member communicated with counterparts in other countries, impressed with what they were doing. When asked what the research was that they based their projects on, they all said it was the US funded research (which the US doesn't take advantage of).