PUTTING TOWN PLANNING IN A LIGHT PERSPECTIVE

The recently published manual of perspective for lighting engineers discusses in detail the factors affecting the making and interpretation of perspective projections. The author examines the importance of perspective to the town planner and road engineer, elaborating on some examples discussed in the manual. Special bright background at tunnel entries can be used to silhouette vehicles as they pass into the tunnel. Perspective studies are vital for the design of multi-level interchanges. Lighting by conventional lanterns can appear confusing whereas high-mast lighting can provide a few groups of lanterns at height which cannot confuse the carriageways. Examples are given of the effect of perspective on small humped roundabouts and long humped bridges. Perspective can be invaluable in the investigation of traffic accidents. Examples are given to show how, on a curved road, approaching traffic can appear to slow down from the viewpoint of a driver waiting to cross. Drivers need time to make decisions; perspectives are important in the provision of an adequate planning time to the driver. (Author/TRRL)