Badly compacted mixtures will develop undesirable properties of low stiffness, bad fatigue resistance, bad durability, etc. that is not expected from a good pavement. This paper is to evaluate the compactibility of hot asphalt mixtures (HAM) made with crump rubber modified bitumen, which was manufactured by incorporating the waste shredded-tire rubber particles in base bitumen in different sizes and concentration. Type of binder and binder viscosity during compaction has a great effect on the compactibility of HAM. Compaction Coefficient (CC), which is variation in porosity line throughout compaction, could be related with the energy needed to compact the mixture. Less energy is needed for the mixture having low CC. Modification of bitumen with rubber makes the mixture less compactable when compared with the mixtures made without rubber. (C) 2007 Elsevier Ltd. All rights reserved.