In Taiwan, the Noise Control Act was amended in 2008 to include new regulations governing ground transportation systems, such as expressways, highways, railways, and mass rapid transit systems. According to the amendment, transport operations and management agencies shall submit traffic noise improvement plans to local competent authorities within 180 days of receiving a notice from local competent authorities and shall follow the improvement plans accordingly. Up to Dec. 2012, 52 filed cases were judged over standard and thus improvement plans were submitted. Nonetheless, 18 of the 41 cases went through evaluation process were not approved after two or more committee meetings. These unsatisfied improvement plans were found to have common deficiencies, such as fail to analyze in-situ factors cause over regulation noise, fail to fully model adjacent transportation systems in computer evaluation models, fail to present reasonable evaluation process that come up with the proposed noise reduction measures, and fail to reasonably evaluate noise reduction effect of the proposed measures using appropriate computer models. Repeated committee meetings for evaluation of these plans cause delay of executing improvement measures, and may induce complains against competent agencies. Consequently, the Environmental Protection Agency initiates this project to diagnose existing problems from angles of regulations, administrative restrictions, consulting firms, as well as executing prediction models, respectively. In-situ measurement of traffic characteristics, as well as associated traffic noise on national expressways were also performed in order to know noise characters of highway pavements, noise barriers, and expansion joints. Meanwhile, focal points of inspection on environmental impact assessment reports regarding to renovation or newly built highway projects are suggested. Moreover, an effort was devoted to collecting regulations and information on noise characters of exterior doors and windows facing transportation systems. All the above tasks were performed during this project. The concluding remarks are intended to serve as a reference for future policy making and improvement plan evaluation.