The Mayor's Ambient Noise Strategy - Greater London Authority

The Mayor’s Ambient Noise Strategy Mayor of London 61
Table 3 ‘Type approval’ noise emission limits for cars, buses and
heavy lorries
Vehicle category 1972 1982 1988/90 1995/96
Levels in ‘drive-by’ test, dB(A) 6
Passenger car 82 80 77 74
Urban bus 89 82 80 78
Heavy lorry 91 88 84 80
source: European Directives 7
4A.9 Ideally, tyres and road surfaces should be designed together. In practice
the wide range of tyres, road surfaces and operating conditions makes
this difficult. A European Directive on tyre noise was delayed by concern
over the parallel need to retain safe grip in all conditions. It was approved
in August 2001 (2001/43/EC). The use of a test surface specifically
designed for lowering the noise of tyres during the vehicle noise test,
means that the results are less representative of those on road surfaces
commonly used in the UK. Within three years of the directive coming into
force, the European Commission is required to report to the European
Parliament on whether and to what extent technical progress would allow
the setting of more stringent levels without compromising safety.
4A.10 Heavier and more powerful cars tend to have tyres that are wider and
therefore noisier. Smaller, lighter vehicles can use narrower profile tyres,
which would be quieter. Quieter-engined vehicles would be particularly
effective in reducing noise where speeds are relatively low, as in much of
London, including traffic calmed areas. Likely moves towards hybrid
electric/fuel cell vehicles will, in the mid- to longer term, make reducing
tyre noise even more important. The way sound energy combines means
that a large proportion of the vehicles on a busy street have to be
replaced with quieter ones before overall ambient noise falls noticeably.
However, quieter vehicles would have more immediate benefits on local
streets and at night. Relevant organisations including boroughs, health
and care organisations, and delivery and servicing firms, should take a
lead in using quieter vehicles, particularly in noise-sensitive situations.
The Energy Saving Trust (www.est.co.uk) has supported market
development of clean fuel vehicles. Similar support for quieter vehicles
needs to be co-ordinated to avoid inconsistent or conflicting messages.