Within a couple of jobs, they had it fine-tuned. There are skis on the market that are similar to it, but basically, we developed our own ski system on the job. The secret is to place the rear skis on the new mat using steel or pneumatic tires or shoes and to place the front ski inboard in the trench or on the previously placed overlay. The old mat should be avoided, whenever possible, as a reference source. Once the new pavement has been placed on the surface, it must be compacted with rollers.
Compaction is critical to reducing the permeability of the mat to give it greater fatigue life.
Roller operators have found that they, too, need to be cautious in their work. If they happen to roll off the new mat just a little and the rollers touch even a small bump on the roadway edge, that bump is transferred across the roller to the inboard side, and the bump is mirrored into the new surface. On our first job, we kept getting bumps on our mat, and we couldn't figure out what it was. We marked every time the machine stopped, every time we dumped a truck, every time a roller pulled off the mat. Rollers have to be operated according to accepted practice and never parked on the mat.