Mapping the pleasantness of an urban environment is an alternative approach, closer to the city dweller's perception, than standardized sound levels cartography. This study reports on modeling pleasantness in urban context using perceptual assessments and sound measurements for specific locations during an urban walk. These assessments have been collected from four groups of approximately ten participants on 19 different assessment locations, along a 2,1 km-long path traveled in both directions. Simultaneously, ⅓ octave band sound levels and audio were recorded. Perceptual and physical models of pleasantness are proposed for specific locations based on multiple linear regressions. A multilevel analysis was performed, and it is shown that a perceptual model that includes perceived loudness joined to the perceived time of presence of traffic, voices and birds explains 90% of the pleasantness variance due to the sound environment variations. Physical models that include the original acoustic indicators that are most correlated with perceptual variables explain 85% of this variance. Thanks to these models, a unique averaged pleasantness value is defined for each assessment location from the perceptual or physical collected assessments. The Pearson's correlation coefficient between the averaged perceived pleasantness and the modeled values from perceptual assessment reaches r(19)=0.98, and r(19)=0.97, with the modeled values from physical measurements. These results make it possible to consider the use of this kind of models in a cartographic context. As the path was traveled in both directions, the presentation-order effect has also been assessed, and it has been found that path direction did not have a significant impact on the pleasantness assessment at specific locations, except when very strong sound environment changes occurred. Finally, the study gives some insights about the retrospective global pleasantness assessment for urban walks. For very short walks between two assessment locations, a recency effect is shown. Nevertheless, this effect doesn't seem to be significant when longer routes are assessed.

This paper examines the effects of two traffic management measures, speed limit reduction and coordinated traffic lights, in a case study area in Antwerp, Belgium. For this purpose, an integrated model that combines the microscopic traffic simulation model Paramics with the CO 2 and NO x emission model VERSIT+ is constructed and validated. On the one hand, reductions in CO 2 and NO x emissions in the order of 25 % were found if speed limits are lowered from 50 to 30 km/h in the residential part of the case study area. On the other hand, reductions in the order of 10 % can be expected from the implementation of a green wave signal coordination scheme along an urban arterial road.

This paper compares two traffic representations for the assessment of urban noise frequency spectrum: (i) a static one, based on mean vehicle speeds and flow rates, (ii) a dynamic one, which considers vehicle interactions along the network. The two representations are compared on their suitability to match real on-field noise levels, recorded on a three lane quite busy street. Representation (i) fails in reproducing spectra envelopes that correspond to this site. In particular, it underestimates low frequencies, what can conceal the real impact of traffic flow on urban sound quality. Representation (ii) greatly improves estimation. It guarantees accurate environmental noise assessment, since it reproduces all traffic situations that are encountered in the site. Moreover, its 1s-based structure allows for the evaluation of spectra variations, with a good accuracy.