I believe the above answers are very good responses, in answering where you might find more information in the Tax Code...see below.
I believe that one could make a case for either expensing or capitalizing the upgrade to your road.
IRS Publication 527 and IRS Publication 535 should be of benefit to your answer.
IRS publication 527 addresses this question in Chapter 1.
Repairs and Improvements:
Generally, an expense for repairing or maintaining your rental property may be deducted if you aren’t required to capitalize the expense.
Improvements:
You must capitalize any expense you pay to improve your rental property. An expense is for an improvement if it results in a betterment to your property, restores your property, or adapts your property to a new or different use.
Betterments:
Expenses that may result in a betterment to your property include expenses for fixing a pre-existing defect or condition, enlarging or expanding your property, or increasing the capacity, strength, or quality of your property.
Safe harbor for routine maintenance:
If you determine that your cost was for an improvement to a building or equipment, you still may be able to deduct your cost under the routine maintenance safe harbor. See Pub. 535 for more information.
