The Strategic Highway Research Program (SHRP) produced a system of materials selection, testing, and mixture design named Superpave, for Superior Performing Asphalt Pavements. The Superpave binder specifications are performance-based; therefore, these binders are known as performance-graded (PG) binders in contrast to the older system of viscosity graded (AC) binders, which are typically used for surface treatments and aggregate precoating (see Item 300). Generally speaking, any paving mix produced hot through a hot-mix plant should be specified with a PG binder.

In the PG binder system, engineering properties believed to be related to the expected performance are measured at temperatures corresponding to the climatic and traffic conditions (maximum 7-day pavement temperature, minimum pavement temperature, loading duration based on truck speed, and traffic volume) of the pavement location. This allows selection of a binder grade that is specifically suited to the particular highway application.

PG binder grade designations are based on climate parameters, as explained below: