When measuring using a straightedge over a joint, what is the recommended height to place the straightedge?

The recommended height to place the straightedge when measuring over a joint is 1 inch. This height is established based on industry standards and best practices to ensure accurate assessment of the surface smoothness of asphalt pavements.

Using a 1-inch height allows for a reasonable evaluation of the surface irregularities that may affect the ride quality and longevity of the pavement. If the straightedge is placed too low or too high, it may either miss smaller imperfections or exaggerate irregularities that are not relevant to the performance of the pavement.

In summary, a 1-inch height strikes a balance that enables inspectors to effectively monitor joint conditions while remaining compliant with specifications set by organizations like FDOT. The choice of other heights would not provide the same level of precision and could lead to misinterpretations of the pavement's surface quality.