ASPHALT EXPANDS AND CONTRACTS with seasonal temperature changes. Consequently, cracks and joints are expanding and contracting when the asphalt move. Fillers do not expand or contract.  Sealing the cracks with a flexible rubberized asphalt that bonds to the crack walls and moves with the pavement will prevent water intrusion. Sealing cracks is a smarter method vs filling because sealing will last longer and cost less.  As part of a pavement maintenance system, crack sealing can significantly reduce pavement deterioration by preventing water penetration into base and sub base layers. This prevention helps to maintain asphalt structural capacity and limits future degradation. In a nutshell, sealing cracks and joints in asphalt extends the service life of the surface treatment and the pavement.  Crack sealing will not improve initial asphalt ride ability, however, the benefits are realized in three to five years when it becomes quite obvious that the asphalt has not deteriorated any further. In fact, asphalt that has been crack sealed has better ride ability five years later than other surface treatments, such as chip seals, micro paving, thin overlays and slurry seals.  In five years these other treatments have come to the end of their life cycle. Parking lots and roads that are crack sealed last longer than those that are not.  Sealing prior to surface treatments enhances the treatment and further extends the asphalt life.  At a time when highway crew manpower is shrinking, along with the funds to support road maintenance, crack sealing stands out as an economical maintenance technique.  The overall success of pavement maintenance programs that include crack sealing, combined with the generally low cost, make crack sealing a highly desired technique.  Crack sealing provides the most cost-effective use of dollars over time compared to other pavement maintenance techniques.