Environmental traffic standards
Creators: name: Barford, Jeromy Charles
Publisher: name: University of British Columbia
Year: 2011

description: The transportation problem is usually seen as one of circulation or accessibility. There is, however, a second dimension which is consistently ignored--that of environmental quality. The first work to consider this second aspect of the problem as an integral part of the planning process was a study conducted for the Ministry of Transport in Great Britain, entitled Traffic in Towns. The report did not develop major concepts of environment beyond a rudimentary level, and there is a critical need to extend its ideas into environmental standards that can be applied in planning situations. It is hypothesized, that environmental traffic standards can be defined, and applied to a particular environment to determine whether the quality of that environment Is above or below that suggested, by the standards. It is first necessary to examine the importance of the environment for man in order to establish a framework for further analysis. Research In the field of sensory restriction shows that varied experience within the environment is necessary to maintain man's behavioural efficiency. The environment is equally important from a physiological viewpoint. Environmental considerations are therefore critically important for planning. The environment must satisfy a range of fundamental needs, which can be defined, into three broad, groups—physiological, psychological, and social. They form a hierarchy of specificity, and are further extended and focussed by the special requirements of a particular type of environment. The needs of a shopping street environment are activity and variety, safety, and comfort. Similarly, the motor vehicle has a set of environmental needs. The motor vehicle is a man-machine system, and the needs can be measured in terms of space and free-flow for the latter, and safety and orientation for the former component. Set against these needs are a series of environmental effects produced by the motor vehicle, which are leading to an increasing deterioration of the physical environment. The major effects are safety, noise, fumes, and visual intrusion, all of which have serious implications for human health and well-being, and. impinge upon all three classes of man's basic needs. Standards are a means of measuring quality in the components of a community's structure. Environmental traffic standards can most conveniently be formulated in terms of performance criteria, which will provide means for testing the degree of hazard or nuisance created by the motor vehicle. To be effective they must be based, on sound data and. objective research, and relate to those groups of people who are most sensitive to the effects. Based, on a review of pertinent literature and research the following environmental traffic standards can be defined: 1. Safety: a) primary basis—that there should be no motor vehicle accidents causing injury or death; b) a desirable volume of 250 vph, and an acceptable volume of 500 vph in both directions. 2. Noise: a) an external sound level of 60d.BA by day and 45d.BA by night in residential areas, and a level of 65d.BA in commercial areas, which should not be exceeded, for more than ten percent of the time. 3. Air Pollution: a) at the adverse level—"oxidant index"—0.15 ppm for one hour by the potassium iodide method; b) at the serious level—carbon monoxide—JO ppm for eight hours or 120 ppm for one hour. 4. Visual Intrusion: a) unilateral parallel parking. A shopping street environment was examined in the light of three of these standards to test both the hypothesis and the applicability of the standards themselves. The quality of the selected, environment was found, to be below that suggested, by the standards for safety, noise, and. visual intrusion during two observation periods. The observations tended, to question the applicability of the pedestrian delay concept used, in formulating the standard, for Safety. There does appear, however, to be a link between the three standards and traffic volumes, and it may therefore be possible to reduce these to one common standard. It is unlikely that simple repair jobs will result in a significant improvement in the quality of existing environments. Dramatic steps are needed in the direction of a new urban form and alternatives modes of movement. Areas for further research are suggested.