The viscosity and penetration based grading systems proven to be inadequate, the strategic Highway Research Program (SHRP) in the US launched a Project between 1987 and 1993 to overcome the flaws in empirical systems.

Cutback bitumen is a range of binders that are produced by adding a hydrocarbon solvent such as paraffin or mineral turpentine to the penetration grade bitumen and mixing them.

In different regions and countries, different Standards and Grading systems are used for determining the quality of petroleum bituminous Binders. The most recognized standards for petroleum bitumen are published by