Abstract:
Ratchaburi old town has been designated as cultural heritage conservation area of in Thailand. A recent study has proposed building a walking route to promote cultural and environmental-friendly tourism in this area. This requires reroute traffic activities on certain roads in the area. Consequently, it increases vehicle amount in the neighboring streets and elevates both air and noise pollution which affects local citizens and tourists health. This study attempts to investigate changes of particulate air pollution (PM2.5 and PM1) and noise level (Ldn) due to the traffic rerouting in the area. The models called R-LINE (version 1.2) and SoundPLAN (version 5.0) were used as tools to simulate dispersions of PM2.5 and PM1, and propagation of noise from the traffic emissions, respectively. Two scenarios were set as follows: Scenarios 1; all vehicles used to drive on the walking street move to an appointed minor road, Scenarios 2; all vehicles on the walking street move outside the area. The changes of both pollutions can be obtained by comparing the models results of the scenarios with the results as of base case (present traffic activities). The two models performance evaluations were conducted prior to carrying out the simulations. Lastly, the co-changes of air and noise pollution were then assessed by means of AirNoise Pollution Reduction Index (ANPr). For the model evaluation results, statistical analyses indicated that both models performances are acceptable. The results of scenario 1 indicated that PM2.5 and PM1 increased 0.3-11.4 % and 0.3-11.4 %, respectively, and Ldn working day increased 2.7-7.9 % and weekend increased 3.0-8.0 %, as compared to base case. These were the consequences of the number of vehicles on the walking street combined with those in the appointed minor road. For scenario 2, as compared to base case., the results showed that PM2.5 and PM1 decreased 2.6-5.6 % and 4.4-11.6 %, respectively, and Ldn working day decreased 0.1-20.6 % and weekend decreased 0.1-20.8 %. This is due to the number of vehicles on the walking street being excluded from the analysis. The ANPr values, obtained from combining the reductions of air and noise pollutions, indicated that scenario 2 - all vehicles present in the walking street move to outside the area - became more suitable. However, this recommends together with providing appropriate parking places with public transportation for the citizens and tourists to travel into the area.