If a complete benefit/cost analysis, including time savings for motorists etc. were done, I wouldn't be surprised to see benefits easily outweigh costs for an interchange.
Has anyone ever seen an interchange project's benefits calculated to include time and fuel savings?
I was just thinking about the difference between stopping at a light and passing through an interchange.
~4,000 vehicles per hour at peak times. All those cars idling while the light was red, then accelerating back to highway speed.
Surely that adds up in terms of fuel use, carbon emissions, etc? Especially over the lifetime of an interchange, 25yrs or more?
Also the minute or two of each person's time they could be using doing something else.
Hmm...