Plans to turn Timaru''s Evans Street into a four-lane highway would result in a much noisier existence for nearby residents, according to a consultant''s study. Claire Haren reports. An expansion of Evans Street to four lanes will result in "unacceptable" noise levels for the most homes along the highway, according to a consultant''s report.
Marshall Day Acoustics was engaged to assess an upgrade of Evans Street between Bridge Road and Wai-iti Road and carried out monitoring at 10 locations along that stretch of road between January 15 and 22, 2007.
The report says that the measured noise levels show that the existing levels at the facades of most nearby dwellings reach levels of 64 to 69 dBA, which is defined under Transit guidelines as a "high noise area", and an increase in ambient noise level of between 2.5 to 4.5dB is expected, depending on a variety of factors for individual dwellings.
"This will produce an unacceptable noise level for the majority of dwellings under the Transit guidelines (both average and single event noise); and also the Transit environmental plan."
The report says that given the large number of residential dwellings in close proximity to a major road, the company recommends that a number of noise control options are considered for the upgrade of the highway.
As well as using a quieter road surface such as open graded asphalt, the report says that for most of the homes, additional noise mitigation measures will be required, particularly given the large number of facades -- estimated at more than 50 per cent -- within 13 metres of the carriageway, either currently, or post-widening.
"For those dwellings within five metres of the carriageway post-realignment, land purchase should be considered."
Another noise reduction option is increasing the level of sound insulation provided by the exposed facades of affected dwellings by, for instance, upgrading the glazing or installation of secondary glazing.
"The use of noise barriers should be considered. However, we believe that these will generally not be practicable as the majority of homes bordering Evans Street gain road access directly on to Evans Street. The large number of penetrations through the barrier would significantly impair the performance."
The report says that the land take to enable the widening will result in:
Bridge Street to McDonald Street, 2.7m to 3.3m added to east side of road
McDonald Street to Waimataitai Street, 2.65m-3.35m added to west side of road
Waimataitai Street to Newman Street, 2.65m added to east side of road, 1.1m added to west side of road opposite the intersection with Belfield Street
Newman Street to Te Weka Street, 2.65m-3.75m added to east side of road
Te Weka Street to Wai-iti Road, 2.46m to 2.65m added to west side of road.
Local Pages