Alabama Department of Transportation
We've allowed a non-contact virtual "ski" for years, but now our specification explicitly allows this. We also allow warm-mix asphalt (WMA) on all but our heaviest-use roads, with up to 35 percent RAP. We are trying to promote WMA and increase our RAP use. We are experimenting with longitudinal joint sealer for surface mixes. We've used tack coat, PG 67-22 and trackless tack. We have had permeable joints in the past (remember the high Ndesign of the early Superpave?), and we are trying to make sure that never happens again. We are in the process to convert all our gyros (state and contractor) to internal angles.