Traffic noise in cities has serious effects on the inhabitants of the cities. Well-known effects are annoyance and sleep-disturbance, but long term health effects such as cardiovascular disease have also been related to traffic noise.

The harmful effects of traffic noise may be partially compensated for by quiet facades and quiet urban areas. Quiet facades provide opportunities to sleep quietly and to relax in a quiet backyard or courtyard, or at a quiet balcony. Quiet urban areas such as parks provide opportunities to restore from stress built up in a noisy environment at home.

According to the European Noise Directive (END) 2002/49/EC, European cities have to produce noise maps and exposure distributions based on noise levels at the facades of dwellings. In addition, the END indicates that cities should quantify how many people have access to a quiet facade, quiet urban areas should be protected.

. . . but there is a problem

Current methods for assessing urban traffic noise and the effects on people focus on the most exposed facades, and are less suitable for quiet facades and quiet urban areas. The QSIDE project will provide a calculation model that is suitable for quiet facades and quiet urban areas. The QSIDE model consists of two submodels:

• an acoustic model for calculating noise levels at quiet facades and in quiet urban areas
• a human-response model for calculating the beneficial effects of quiet facades and areas.

The acoustic model is developed by experts on urban acoustics, dealing with the complex phenomenon of sound propagation between street canyons.

The human-response model is developed by experts on the effects of noise on people, employing advanced statistical analyses of noise survey data

A typical example

Traffic noise levels at dwelling facades in cities, expressed as day-evening-night levels, vary typically between 40 dB at quiet locations and 75 dB at very noisy locations.

As an example, we consider dwellings with a level of 65 dB at the most exposed façade. From statistical noise surveys we know that about 15% of the people living in such dwellings are highly annoyed by traffic noise.

The idea of QSIDE is basically to develop and employ a refined representation of noise exposure of dwellings. We expect to find that people in dwellings with 65 dB at the front and 50 dB at the back are better off (less annoyed) than people in dwellings with 65 dB at all façades. We estimate that the difference is of the order of several percentages of highly annoyed people (preliminary estimate).

QSIDE guidelines for EU cities

The QSIDE consortium includes the municipalities of Amsterdam and Gothenburg, two cities with noise policies that already take into account the beneficial effects of quiet facades. In Amsterdam, a façade level higher than 48 dB is in principle only allowed if the dwelling also has a quiet façade with a level below 48 dB.

The QSIDE project will make it possible to quantify the positive effects of quiet façades and quiet urban areas. If the effects turn out to be large, this will give further support to the implementation of quiet facades and areas in urban noise policy of EU cities.

To facilitate and promote this implementation, the QSIDE project will produce a practical document with guidelines for EU cities, based on both the QSIDE results and practical experiences in Amsterdam, Gothenburg, and other European cities.

Structure and funding of the QSIDE project

The QSIDE project is organized in seven Actions, as indicated in the figure below.

QSIDE is an EU project funded within the Life+ programme (LIFE09 ENV/NL/000423).