I agree it sounds astronomical but… I actually understated the costs according to ARTBA.
There is no single answer to this question. Construction costs per mile of road depend on location, terrain, type of construction, number of lanes, lane width, durability, number of bridges, etc. It costs more to build a new road than to rehabilitate a road or add lanes. Roads cost more to build in urban areas than in rural areas. Roads in mountainous terrain are more expensive to build than roads on flat land.
Nonetheless, some states have developed cost models to guide planning for their highway construction programs. These models give a ballpark figure for various kinds of highway improvements. The following are some examples:
Construct a new 2-lane undivided road — about $2 million to $3 million per mile in rural areas, about $3 million to $5 million in urban areas.
Construct a new 4-lane highway — $4 million to $6 million per mile in rural and suburban areas, $8 million to $10 million per mile in urban areas.
Construct a new 6-lane Interstate highway — about $7 million per mile in rural areas, $11 million or more per mile in urban areas.
Mill and resurface a 4-lane road — about $1.25 million per mile.
Expand an Interstate Highway from four lanes to six lanes — about $4 million per mile.
The Florida Department of Transportation has published its generic cost per mile information for 2013 online. The Arkansas Highway Department’s estimated cost per mile for 2013 is available online.
The Missouri Department of Transportation has a slightly different estimate.
Average Costs to Build or Maintain Missouri Highways:
Cost to Resurface (per lane mile)*
Major Highway $157,000
Interstate $164,000
Cost for New Construction (per mile)**
Two-Lane Highway $1.8 million
Four-Lane Highway $4.6 million
Kansas City, MO (where I live) says that it’s a minimum of $2m per lane per mile to reconstruct, but this is a verbal figure from Public Works, not a publicly documented figure — at least, not that I’ve seen publicly documented. It lines up with the ARTBA estimates adjusted to MO cost of living.
Thanks for asking Varun, and happy to answer any other questions you might have.
