Urban background noise mapping: The general model

Download
Weigang Wei
Dick Botteldooren
Timothy Van Renterghem
Maarten C J Hornikx
Jens Forssén
Erik M Salomons
Mikael Ögren

Surveys show that inhabitants of dwellings exposed to high noise levels benefit from having access to a quiet side. However, current practice in noise prediction often underestimates the noise levels at a shielded façade. Multiple reflections between façades in street canyons and inner yards are commonly neglected and façades are approximated as perfectly flat surfaces yielding only specular reflection. In addition, sources at distances much larger than normally taken into account in noise maps might still contribute significantly. Since one of the main reasons for this is computational burden, an efficient engineering model for the diffraction of the sound over the roof tops is proposed, which considers multiple reflections, variation in building height, canyon width, façade roughness and different roof shapes. The model is fitted on an extensive set of full-wave numerical calculations of canyon-to-canyon sound propagation with configurations matching the distribution of streets and building geometries in a typical historically grown European city. This model allows calculating the background noise in the shielded areas of a city, which could then efficiently be used to improve existing noise mapping calculations. The model was validated by comparison to long-term measurements at 9 building façades whereof 3 were at inner yards in the city of Ghent, Belgium. At shielded façades, a strong improvement in prediction accuracy is obtained.

MEET US


6
Oct

Open seminar with Mistra SAMS international scientific advisory...

Mistra SAMS international scientific advisory panel (ISAP) is visiting Stockholm, and the program will host an open seminar where the panel members will give talks in their area of expertise.
19-20
Oct

ERPUG 2017

The five year anniversary of  European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017. 

LATEST NEWS


2017-07-05

Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...


2017-06-29

Tomas Svensson new director-general

Tomas Svensson was today appointed Director-General of VTI. Tomas has been acting Director-General since January 2017. 


2017-05-30

Crash testing bicycles at VTI

For the first time single bicycle crashes have been simulated at the VTI crash safety laboratory.


2017-05-15

A case study exploring firefighters’ and municipal officials’ preparedness for electrical vehicles

A VTI-study presents a social perspective on new vehicle technology. It explores the self-reported preparedness of the fire departments (i.e., rescue services) in Sweden’s three largest cities regarding rescue operations involving electrical vehicles (EVs).


2017-05-02

Pioneering research on and about bicycles at VTI

Under what circumstances might cyclists lose tyre grip? What actions could then be taken to prevent a crash? VTI is currently developing a theoretical model of the behaviour of bicycle tyres during braking and steering in different situations and on different...


2017-05-02

Virtual pedestrians create efficient stations

If more people are to choose sustainable travel, then the public transport stations of the future must be designed so that pedestrians can get where they are going quickly, without congestion or queues. The Swedish Road and Transport Research Institute (VTI)...