They build roads into timber stands for sales they know the taxpayer will have to subsidize. In the private sector, capital investments are only made if their future income streams have a positive net present-value. In the public sector, such calculations are often irrelevant to the decision-maker's welfare. The important difference in the above comparison is that while Ford must use its own money, the Forest Service gets its funds from you and me. However, exorbitant economic costs are only one argument against unnecessary road building.
Environmental costs are also high.
They are magnified when traversing roads are built into the high, steep and fragile backcountry of the Rockies and Alaska. In constructing roads, large amounts of soil, sand and rock are displaced. The result is a tract of earth loosely compacted, devoid of vegetation, and subject to erosion. It is a rule of thumb in forestry engineering and forestry hydrology that 90 per cent of all erosion traceable to timber management is caused by road building. This erosion and subsequent siltation muddy and fill trout streams, fisheries, irrigation systems, and decreases the quality of water.