The relationship between air quality and transportation

The Transportation Conformity Rule has had a significant impact on the work and responsibilities of transportation planning agencies since the Clean Air Act Amendments of 1990. Although sensible in its design, the rule has resulted in a practice of vague calculations and inefficient policies. Transportation Control Measures, the panacea to urban air pollution and the key to sustainable urban design, produce small improvements to air quality and are often not worth the cost. Technology, on the other hand, at a level which we are already paying for and receiving, will continue to improve the efficiency of the automobile which has resulted in much of the air pollution control to date and is expected to continue to progress in the future. Unlike Transportation Control Measures, solutions aimed at the cause of "excessive" travel, such as solutions geared towards controlling the dispersion of work places, the value of labor over goods, and the desired residential densities of our suburbs and exurbs can have profound efficiency effects on transportation spending as well as air pollution control. Until air quality and transportation planning agencies stop meeting the precise calculations of the conformity rule and use their tools and skills in a much broader fashion, clean air will continue to be an academic nuisance and not a proactive goal in most urban areas.