Highway pavement with high functioning The high-functioning pavement has been in service on trial since 1989. But design method and operation techniques were not established in the first stage of operation and the asphalt used was not for high-functioning pavement. As a result, the function was greatly lowered after 1 year from operation. After that, on the basis of indoor experiment and trial operation of all kinds, the operation and design guildline were set up in 1991, and durability has been greatly improved since then. Rutting Deformation The amount of wheel trace is in general about 1mm in the area where there are neither snowfalls nor temperature drops in the winter season[hereinafter referred to as "general area"] and in the snowed cold area(except the North Sea, hereinafter referred to as "cold area"), far better durability than the existing dense pavement(about 2mm a year). In contrast, the amount of rutting trace in the cold area is 2mm annually, far greater than in the general area but is the same amount as in the dense pavement in the general area. Drainage function The drainage function is one of the key features of JH high-functioning pavement. It is expressed in time needed to drain 400ml of flowing water. The drainage function of high functioning pavement is under 10 seconds immediately after the construction. The function in the general area weakens a little bit 1 year after the start of operation, but stays in a desirable condition without big change up to 5 years after the building. Also, it gradually decreases as time passes by and deteriorates in the cold area faster than in the general area after 5 years. It is thought that it is caused by dirts from snow-chains and snow removing works because air voids are clogged by the dirts. Drainage and noise-reduction is generated by air voids in the high-functioning pavement. If earth and dirts clogs the air voids, the functions decrease. For this reason, JH makes efforts to increase durability by lowering air void rate in the snow cold area, but reduction of functions by lowering air void calls for the change of stone grains used in pavement to produce high-quality air voids(sustainable air void). In preparation for the air void clogging, JH introduces a high-pressure cleaning car to be able to restore them. In the past, water was never poured onto the pavement. This high-functioning pavement has been being confirmed to by far superior to conventional ones by drivers.