Shrubs and trees have been used to reduce the visual impact of a highway on the surrounding area and to enhance the diversity of prospect from a vehicle on the highway. The conditions under which these plants have to survive and flourish have been quantified. Particular attention has been paid to effects of salt usage, and the information gathered has been used to identify areas of the country of varying intensity of salt hazard. The performance of plant species has been assessed by controlled experiments and by field trials. Information from the literature has also been used to classify 80 plant species as either tolerant, intermediate or sensitive. Using this information, together with that on the salt hazard, suitable plant species can be selected for use in particular locations. (Author/publisher)
Abstract