Role of noise pollution on urban design in new cities (Case Study :New Cairo)

Noise is one of the main factors that can negatively affect human health and willingness towards living in a particular location. Over 30% of Europeans experience unwanted sound, especially in intensively urbanized areas (12). Noise can interfere with residential and community amenity and the utility of noise-sensitive land uses. Noise exposure can lead to a range of adverse effects including sleep disturbance and annoyance, impairing cognitive learning in children at school, psychological disorders, negative effects on the auditory system, obesity and an increase in the risk of cardiovascular effects (8), for these reasons the impact of noise can be a material consideration in the determination of planning applications and sustainable development. A lot of factors associated to urban planning have a considerable effect on volume of traffic, vehicles distribution, traffic conditions, and it is known that, from a temporal and spatial point of view, the most important source of noise in cities is road traffic (19). The World Health Organization (WHO) had estimated the burden of disease from traffic-related noise within the western part of Europe and concluded that on each year there is a loss at least one million disability-adjusted life years(DALYs)(38). Good acoustic design seeks to encourage and promote design outcomes that are proportionate to each development site, so the planning system has the task of guiding development to the most appropriate locations. It will be hard to reconcile some land uses, such as housing, hospitals or schools, with other activities which generate high levels of noise, but the planning system should ensure that, noise-sensitive developments must be sited away from major sources of noise (such as road, rail , air transport and certain types of industrial development)(22). The main aim of this study is the approach regarding the noise problem solution, instead of studying sound insulation materials and techniques, it focuses more on general urban planning regarding the shape of buildings, street orientations, positioning new parks , constructing earth embankments and traffic congestion control in order to reduce the noise impact on the citizens outside and inside their homes. Development plans can provide the policy framework within which these issues can be weighed and local planning authorities should consider whether it is practicable to control or reduce noise levels, through the use of planning obligations (21). The research study had analyzed the relationships between urban noise and different specifics aspects of urban design through specific methodologies for noise pollution assessment and its relation to urban planning. In this way, the fact of finding a sustainable city could be closer, at least with respect to noise pollution. The study was done on most residential areas in the city of New Cairo. The results had shown that urban planning must be made with some logical considerations regarding sound propagation and amplification mechanisms in order to improve the comfort and people wellbeing in future developments. The methods followed for reduction of noise propagation and good urban planning include low-height barriers , ground treatments; acoustically absorbing facades and roofs of buildings, building morphology and quiet side and vegetation. Moreover, treatments at source consider tire friction, road condition, engine (whether electric or combustion), driving speed and acceleration, and further vehicle restrictions play an important role in noise mitigation.  Quantitative reductions, in decibels, as well as qualitative aspects are presented. Conclusions: The described possible improvements to the urban sound environment, with focus on road traffic noise and building design as the dominant impairing factors, inform us about how a good urban sound environment can be reachable. However, to reach a good sound environment in reality, the work process of applied urban sound planning demands efforts across disciplines at early-stage planning, instead of traditional noise control applied late in the planning process.