EPA Preserves Program to Minimize Emissions of Nitrogen Oxides

Recently EPA made an evaluation of a current program. ("The program, known as Prevention of Significant Deterioration (PSD), addresses the need to allow growth while maintaining air quality in areas that are already clean.") They found the program is working to minimize the impact of nitrogen oxides (NOx) emissions.

As the article stated, "Significant deterioration" is defined as the maximum allowable pollutant concentration increase - also known as an "increment" - above an existing baseline concentration for an area. An increment is established for areas (e.g., counties) that states designate as attaining national air quality standards. Emissions increases that cause the increment to be exceeded for a given pollutant are not permitted.

NOx emissions is a dangerous factor which influced enviroments greatly. Except PSD, is there any other better approach to deal with and solve the problem? Do you think states should concentrated on one significant program and put all money, time, or human resources on this one or sperate the cost on different programs? Which one will benefit more to the whole society?