Study Reports

 

 

1.1     The Executive Council (ExCo) endorsed at its meeting of 14 November 2000 a policy to address the noise impact of existing roads on residents. Direct engineering measures in the form of barriers or enclosures would be considered where practicable at existing roads generating noise level exceeding 70 dB(A) L₁₀(1 hour) provided that the following guiding principles are complied with:

 

 

1.2   Whilst about 30 existing road sections had been preliminarily identified as being technical feasible for retrofitting barriers till 2001, there had been increasing requests from the public, District Council (DC) and Legislative Council (LegCo) members on installing barriers on other existing roads. However, there would be change of circumstances such as increase in traffic flow, change of nature of land uses, redevelopment of residential buildings, etc. that may affect the technical feasibility of road section for retrofitting barrier.  The government had conducted review studies as necessary following the guiding principles to identify any further road sections for implementing engineering solutions.

 

1.3    The review studies included a total of 50 road sections as shown Appendix 1.

 

1.4    The extent of each road section studied is shown in the site plans in Appendix 2.

 

 

 

 

 

 

 

2.3       The review study has been conducted based on a desk-top review of the relevant Outline Zoning Plans (OZPs) and 1:1000 scale survey maps produced by Lands Department (Survey and Mapping Office) as well as the Traffic Aids Records provided by the Transport Department (TD). These OZPs and survey maps provided information such as road alignment, footpath, cycle track, building location and type, land-use, etc. Other traffic-related features such as traffic signs, pedestrian crossing facilities, bus lanes, etc. were identified based on the Traffic Aids Records. Site visits were conducted to verify existing situation and identify if there were any recently constructed elements.

2.5       This Guiding Principle is the fundamental requirement for retrofitting barriers on existing road sections. Structural space must be available for constructing the foundation in addition to accommodating the barriers themselves. For retrofitting barriers on at-grade roads, a minimum space of 1m is required for foundation and column even if short pilings are used for the foundation. Figure 1 illustrates the process of the space availability considerations.

2.6       A minimum horizontal clearance of 1m should be provided between kerb of carriageway and panels/columns of barriers on the footways, verge or central reserve as referenced to Transport Planning and Design Manual (TPDM) Volume 2 issued by Transport Department.   In case that any street furniture such as untensioned corrugated beam barrier is proposed between the carriageway and the barriers, additional space availability concern should be considered.

2.7       In association with the minimum space for the foundation and horizontal clearance as mentioned in Sections 2.5 and 2.6, respectively, a minimum space of 2m from the road kerb is needed. In case that any street furniture such as untensioned corrugated beam barrier is proposed between the carriageway and the barriers, additional space availability concern should be considered. Besides, adequate additional roadside space should be reserved for the provision of traffic signs and associated facilities as necessary.

2.8       It is necessary to avoid obstruction to pedestrian flow according to the requirement of TPDM. After erection of the barriers, space of 1.6m (2.0m after revision of the TPDM) to 4.5m should be maintained for unobstructed pedestrian passage.

2.9       For the general requirement of a vertical barrier on spread footing, the minimum space requirement is 3.5m. For locations that involve flyovers, where pile is not feasible for the foundation of barrier, an independent structure for barriers is required instead. A construction space of more than 3.5m for the foundation may be required. The structural design of strengthening the existing flyover will need to be considered in detailed design stage.

2.10    Fire safety in a building is determined by a number of factors, one of which is the means of access enabling fire-fighting personnel to rescue and fight fire. This Guiding Principle aims to maintain access for fire-fighting personnel. Therefore, barriers should not be provided at the EVA points. Also, it is essential that affected major building facades for fire safety and rescue purpose should be within the reach of the fire engines. In general, EVA with a minimum width of 6m should be provided adjacent to affected facades. The obstructed distance between the fire engine and the major building facade for fire safety and rescue purpose should be less than 10 m. Furthermore, for flyover situations, Fire Services Department (FSD) requires that a 4.5m horizontal clearance between the outer edge of the flyover structure and the adjacent building facade be maintained. Figure 2 illustrates the process of emergency access considerations.

2.12    This Guiding Principle aims to ensure that the new structures will not undermine road safety or impede pedestrian and vehicular movements. The noise barrier should not be erected at locations where they may pose any hazard to road safety or reduce the degree of road safety. This is particularly essential for barriers close to an existing intersection as it could affect the visibility of both pedestrian and drivers. Also, provision of a barrier along a bend in the road may obstruct the sight line for stopping safely. The logic is that the principle of “Seeing and be seen” must not be violated.  The sight distance should not be less than the desirable minimum as stipulated in TPDM. Figure 3 illustrates the process of road safety considerations.

2.13    It is necessary to avoid having the noise barrier cause an obstruction to pedestrian flow. According to the TPDM, space ranging from 2m to 4.5m should be maintained for pedestrian passage in urban situations depending on pedestrian volume.

2.15 Apart from commercial activities, the new structure for noise barriers could not disrupt any social activities, e.g. pedestrian crossing, landscape appreciation and recreational place access. Figure 4 illustrates the process of socio-economic considerations.

 

 

 

 

 

 

 

 

 

2 barriers, one of which was shorter than 100m, near Tsing Shing Court were identified “not technically infeasible”. The acoustical performance of the identified barriers would be low (less than 10% of the dwellings at Tsing Shing Court and Cheung Hong Estate would be benefited). Moreover, erection of barriers in front of Tsing Shing Court only may not be well accepted by the residents of Cheung Hong Estate, further study of the technical feasibility is not recommended.

 

 

 

 

 

 

 

 

1 barrier near Yee Kui House, Tsing Yi Estate, and 1 barrier near Tsing Fai San Tsuen were identified to be “not technically infeasible”.  In 2012, the noise situation was reviewed. The noise measurement results revealed that the road traffic noise at Yee Kui House (the worstly affected NSR) was below the 70dB(A) criterion. Thus, the noise barrier is no longer justified. At Tsing Fai San Tsuen, the measured road traffic noise level still exceeded 70dB(A). Erection of the identified barrier near Tsing Fai San Tsuen would require felling or transplanting of the mature trees along the road section. Moreover, the acoustical performance of the identified barrier near Tsing Fai San Tsuen would be low (no more than 10% of the dwellings along the road would be benefited),. Therefore, further study of the technical feasibility is not recommended.

 

 

3 barriers, 2 of which were less than 100m, were identified to be “not technically infeasible”.  In 2012, the noise situation was reviewed. The noise measurement results revealed that the traffic noise levels were below the 70dB(A) criterion. Thus, the retrofitting noise barriers are not longer justified.

 

 

 

 

 

 

 

 

 

 

 

 

6barriers were identified to be “not technically infeasible” with 5 of them less than 100m in length. As Tsing Tin Road is within the study area of Highways Department’s Tuen Mun Western Bypass Project (TMWB), the interfacing issues with TMWB and the exact extent of barriers would be reviewed later when more information is available from TMWB Project.

 

 

5.1    50 road sections were reviewed in the studies. It was found that 3 road sections were not generating excessive traffic noise. Out of the remaining 47 road sections, retrofitting noise barrier on the whole sections would be technically infeasible.

 

5.2    The review studies identified 29 road sections that are technically not infeasible to provide mitigation measures in the form of noise barriers. Nonetheless, further study of the feasibility of retrofitting noise barriers on 15 road sections out of the 29 are not recommended due to various considerations such as updated noise environment and acoustical effectiveness.