May 01, 2013 · 4. ESTIMATING ROAD CONSTRUCTION UNIT COSTS – FAO. The unit cost of road construction in dollars per kilometer is the sum of the subunit . The surveying production rate in km per hour is equal to the number of .. Excavation rates in rock vary with the size of job, hardness of rock and other .. The culvert crew uses a flatbed truck to transport themselves and the pipe each day.