Isn't that under "Resurface existing lane" and "Improve shoulder"? Yes there are other costs associated with road upkeep, from vegetation trimming to pothole repairs. But I would think the first two are rather major parts of upkeep. To make things easy, assume a 10 year interval between these maintenance items so divide those line items by 10 for the annual cost.

Definitely not a small number considering the installed road base…