Like Jiang

Combined acoustical and visual performance of noise barriers in mitigating the environmental impact of motorways

This study investigated the overall performance of noise barriers in mitigating environmental impact of motorways, taking into consideration their effects on reducing noise and visual intrusions of moving traffic, but also potentially inducing visual impact themselves. A laboratory experiment was carried out, using computer-visualised video scenes and motorway traffic noise recordings to present experimental scenarios covering two traffic levels, two distances of receiver to road, two types of background landscape, and five barrier conditions including motorway only, motorway with tree belt, motorways with 3 m timber barrier, 5m timber barrier, and 5m transparent barrier. Responses from 30 participants of university students were gathered and perceived barrier performance analysed. The results show that noise barriers were always beneficial in mitigating environmental impact of motorways, or made no significant changes in environmental quality when the impact of motorways was low. Overall, barriers only offered similar mitigation effect as compared to tree belt, but showed some potential to be more advantageous when traffic level went high. 5m timber barrier tended to perform better than the 3m one at the distance of 300 m but not at 100 m possibly due to its negative visual effect when getting closer. The transparent barrier did not perform much differently from the timber barriers but tended to be the least effective in most scenarios. Some low positive correlations were found between aesthetic preference for barriers and environmental impact reduction by the barriers.

Strategies for Modern Schemes for the Inner Ring Road of Sheffield

The Inner Ring Road of Sheffield was first proposed in the 1930s and mainly constructed in late 20th century. While trying to serve effectively as traffic arteries, the ring road, which has required massive demolition, is somewhat physically arbitrary, appearing like a huge scar on the existing urban fabric. This chapter investigates the Inner Ring Road schemes in the early-mid 20th century, to explore how the project had originally been envisaged and decisions were made, as well as the impact it imposed and the indication it revealed. It seems modern schemes in that period were very largely based on engineering thought, and the social ideas in the meantime encouraged a centrally controlled approach and a highly ordered and developed urban vision. While the outcome of the road had been improved due to much broader concerns over the following decades, many original ideas and features in the schemes in the early-mid 20th century are retained, and continue to affect the current city. As highway construction will still be needed as cities keep developing, it is important to have a thorough understanding of how the early schemes were conceived and worked out in a time when motor traffic emerged as a dominant type of movement in urban areas.