>The cost of maintenance for tunnels is almost certainly higher than that for surface roads. Pros would include avoiding the freeze thaw cycle that destroys ro

>The cost of maintenance for tunnels is almost certainly higher than that for surface roads. Pros would include avoiding the freeze thaw cycle that destroys roads in much of the country. Tunnels could also allow pollution mitigation to take place if internal combustion engines were used, which is simply impossible on open highways. Cons include an obviously higher initial capital expenditure. I suppose we need to get down to a cost per person moved metric over something like 30 years to more objectively compare.