computerised computerized equipment hardhats helmet laser level levels measurement measuring men safety skilled skills surveying surveyors technology theodolite triangulation tripod workers workmen access bollard calculating calculations color colors colour colours flowers man pavement plants roadside shrubbery shrubs surveyor trees tripods work worker workman abstract appearance building compacted compacting firm firming flatten flattened groundwork leveled leveling levelled levelling mark marked preparation prepared preparing sand sandpad yellow yellow-sand