The Contribution Of Highways To GDP Growth

This paper constructs updated measures of productive highway capital stocks at the total, Interstate, Non-interstate, and Local System levels to estimate the contribution of all highways (all public roads) to GDP growth. It presents three types of contribution to GDP growth estimates and an experimental structure estimate reflecting the quality of bridges. These three contributions, estimated from the viewpoint of a national income accountant, are: The contribution of highway investment to growth in GDP, The contribution of highway capital input to growth in adjusted GDP, and The contribution of highways gross output to growth in adjusted U.S. gross output.