where t is the number of years after the bicycle lane is installed, B represents the
benefits in one year, and i is the social discount rate.
Then, total construction costs can be estimated, assuming that the cost for
construction of the bicycle lane will be funded by borrowing and are paid back in
equal installments. Construction costs, estimated from the Colchester-Truro
Bikeways Plan (2010) are amortized over a 20-year period using a 3.5% interest rate (or 2.5% or 7%). Net present value of the construction costs are