Creating Quiet City Zones by noise charges and quiet vehicles. Part two: Noise reduction effects

摘要

One important subject in the EU directive 2002/49/EC regarding noise maps and action plans is to establish or preserve quiet areas. A study within the EU FP6 project "Quiet City transport" (QCITY) have analysed the possibility of creating Quiet City Zones. The concept is to utilize noise charges and quiet vehicles for reducing traffic flow and vehicle noise source emission in the zone by use of closing gates and charges for noisy vehicles. Such measures will affect traffic in many ways. Some people will switch to other transport modes to escape the closing gates or the fee. Others will choose another destination, while people normally travelling through the quiet zone may change route. Because low noise vehicles were exempted from the fee, some people will also change to a low noise vehicle. Traffic models were used to resemble the effects on traffic flow, using a prediction system modelling the travel demand and transport system of the entire Stockholm County. Traffic flow data from each simulation were used as input for creating noise maps. Results reveal that when only quiet vehicles were permitted, the noise reduction within the zone is 12-16 dB(A) units. With a 2-Euro charge, the reduction is approximately 7-9 dB(A) units. The noise reduction is partly caused by reduced traffic flow inside the zone and partly due to the lower noise emission from the vehicles operating in the zone. Due to the traffic restrictions in the quiet zone the traffic flow on boundary rerouting streets just outside the noise restricted zone will increase by 1-3 dB(A) units. The noise leakage effect into the quiet zone is though small. We believe that co-modelling traffic flow and noise effects for creating quiet zones is an interesting new concept. Therefore the information will be presented in two consecutive papers. The first paper (KTH) will report the modelling of traffic flow effects and the second consecutive paper (Acoustic Control AB), will report on the noise reduction effects.