Natural materials, especially those from the site or nearby, can reduce impact and blend into the landscape. Used for unsealed surfaces they also present a coarser texture than sealed surfaces and so tend to fit better into the wider landscape. Sealed surfaces such as bituminous macadam or asphalt are darker in colour, usually black, and very fine in texture. However, this can be ameliorated by using a spray-and-chip top layer (tar spray with spread and rolled chippings) of local material. The same technique can also be used on an unsealed surface in order to improve wear and tear. This is the kind of surface finish commonly used on rural roads in many places. The spray-and-chip finish can be added to the access road but not the parking bays, where wear is less. The slight difference in texture and colour then helps to delineate the two areas.
Climate
In hotter, dry areas dust from unsealed surfaces can be a serious problem all through the summer. Any vehicle travelling even at slow speeds tends to throw up dust, which is very uncomfortable when breathed in or deposited on skin or clothing. In other places a very wet climate may result in frequent potholing on unsealed areas with much reduced surface quality. Snow clearance in winter may be necessary, and unsealed surfaces are more easily damaged by snow ploughs than smoother, sealed ones.
