In an earlier study for the Science and Engineering Research Centre (SERC I) 1986 to 1989, 74 sites of 100 metre length were observed manual at 6 month intervals and rates of deterioration advanced for 8 condition indicators rutting, wheel track, cracking etc. At the inception of the completed study (SERC II) 30 of the original sites remained and another 90 sites were added in four highway authorities including rural counties and urban cities. Now there remains only 70 sites, where the terminal conditions prior to maintenance treatment have been documented and used as the basis for the development of maintenance strategies. In those later studies, machine based surveys of profile, skidding resistance and deflection have been obtained and some preliminary findings of machine vis-a-vis manual condition surveys are advanced. Preliminary work has also been done on determining deterioration rates in relation to level of absolute condition. This enables predictions which are not explicity time based. There are indications that changes in time are non-linear. Further research is planned over 2 years to complete and consolidate the decade of research insights into minor roads and to further develop knowledge based systems for minor road maintenance strategies. (A)
Samenvatting