Background/Objectives and Goals The MMDA-implemented Modified Unified Vehicle Reduction Program, a type of Traffic Demand Management, is a road rationing scheme that addresses the issue of the traffic congestion through driving restrictions. The study will determine the effectiveness of the UVVRP in not only the reduction of traffic congestion in Metro Manila but also the atmospheric air quality. Air quality has been drastically declining due to the emissions brought by mobile sources. The results in this study have shown that transport policies and air pollution regulations would have a very significant impact on urban transport inefficiencies like congestion. Methods The researchers need to estimate the unknown parameters. A regression analysis must be carried out to avoid the risk of autocorrelation of errors between explanatory variables. In order to avoid this, we used the Two Stage Least Squares (TSLS) method to determine the impact of the UVVRP on air pollution based on time-series data at the metro-wide level. Simultaneity problems also exist. The econometric specifications estimated the instrumental variables which was only correlated to the explanatory variables. Results/Conclusions/Contributions Based on the research, since congestion has an insignificant impact on air pollution and the current specification of UVVRP does not greatly impact the congestion, thr UVVRP policy does not impact the air pollution in Metro Manila. This is opposite to the UVVRP version in other countries where it aims in reducing air pollution. The researchers suggest modifying the coding scheme by reducing the vehicle usage from once a week into an odd-even scheme. This may be drastic but it certainly calls for the situation given that there is a lot of current infrastructure construction. This study would interest any polices that are related to addressing congestion and pollution problems.