Comparative noise levels from trams and buses and cars


From Professor Lesley.  ” Let’s also concentrate on the environmental benefits, no pollution emitted in streets (zero carbon with renewable generation), can replace buses to further reduce toxic pollution levels AND quiet operation (WHO max urban level 55dB(A), compared to >70dB(A) on most UK urban main roads. Some or all or these benefits are demonstrated by UK tramways ?


“The paper concludes that from measurement across operational circumstances there should be little perceived difference in noise from buses and trams, but that proportionately cars can generate significant emissions.”

“From the above it can be seen that the regular passage of cars
can have significant influence on noise in the urban
environ;ment, relative to buses and trams, which pass by at
lower frequencies.”


From the above it can be seen that in the round, across all
conditions, the noise from buses is potentially no more significant
than that from trams. Bus engine noise, especially under heavy
acceleration, can generate larger noise emissions than trams, but
under certain conditions trams do generate more noise than buses,
for example on street track at speed. Cars as expected are quieter
than both modes although, again under aggressive driving, cars
can also generate significant noise impact.
If the effect of overall service noise is considered by comparing
relative noise effects between the SEL values, the passage of eight
cars at 30 mph (77 dB(A)) gives a combined SEL of 86 dB(A), which
is equivalent to the tram at 30 mph on the street, and similarly
three to four cars equate to the SEL measured for one bus.
Three buses at 81 dB(A) SEL equate to one tram at 86 dB(A) at
speed. The situation becomes somewhat reversed when
considering trams at slower speeds (e.g. when leaving stops), or
when they are at speed on ballasted track. In such circumstances
two to three tram passes equate to the noise from the equivalent
passage of one bus. This becomes significant at high flow rates as
trams carry four times as many passengers as a bus. Typical tram
services run at 10 min frequencies in each direction, giving a total
passage of 12 trams/h in a given area. To provide the same level of
passenger capacity this would require in the region of 50 buses (a
bus every 2 to 3 min each way) with the consequent effect on
From the above it can be seen that the regular passage of cars
can have significant influence on noise in the urban
environ;ment, relative to buses and trams, which pass by at
lower frequencies.



It can be seen that there is expected to be an increase in road traffic annoyance between now and 2011
and 2026 without the tram. This is caused by the expected general increase in road traffic. In
comparison there will be no significant change in noise annoyance caused by the tram in either 2011
or 2026.
Numbers of households affected by perceptible increases and decreases in noise levels (ie of more
than 3dB) have also been estimated using a similar technique and are reported in Table 13.13.
Table 13.13 Households Exposed to Perceptible Noise Changes
With Scheme Households experiencing
increase in road traffic noise
levels of >3dB
Households experiencing
decrease in road traffic noise
levels of >3dB
2011 0 50
2026 0 50
Based on the traffic modelling data available at this stage, no properties are predicted to experience
perceptible increases in noise and there will be a small number experiencing a perceptible decrease
suggesting a very small beneficial impact from Line One operation.