> but a bridge like that would probably costs >$1M today. For comparison, from a brief search for “cost per mile of road”. * $2-3 million per mile of two-lane

> but a bridge like that would probably costs >$1M today. For comparison, from a brief search for “cost per mile of road”. * $2-3 million per mile of two-lane rural road. * $4 million per mile to expand a highway from four lanes to six lanes. * $120k/mile/year in road maintenance.