Page 35 - 2022

for different types of vehicles, speed, traffic volume and honking. The noise were
classified with regards to frequencies and analyzed. Parameters of noise level monitored
were Leq, L10, L50, L90, Lmax and Lmin. All the above measurements and observations
were then rationally processed using SPSS 14 analysis.

Prima facie it is found that the traffic noise level is higher than permissible limits fixed by
GPCB and CPCB. In all of the selected intersections of residential, commercial and
industrial, the noise level is found to be 82 to 110 dB which is higher than the permissible
limits of 45, 55 and 75 dB prescribed for residential, commercial and industrial areas.
Considering the projected population of 100 million by 2030 Ahmedabad city and the
growth in the number of vehicles, the noise level will exponentially increase and could be
detrimental to the health of citizens. It is therefore utmost necessary to check and control
all the parameters responsible for noise pollution effectively.

It is observed that the noise level is proportional to the traffic volume. Heavy vehicles and
auto rickshaw create more noise than another type of vehicles. In the case of commercial
zones, three wheelers, i.e. auto rickshaws followed by two-wheelers contribute the noise
the most; whereas, in the industrial zone, heavy vehicle’s noise contribution seems to be
more.
It is found that honking has a significant effect on noise level. It is to note that noise level
is increased by 4 to 5 dB on honking compared to the condition without honking. In
Ahmedabad, insufficient road widths, absurd parking, building heights and traffic volume
is mainly responsible for this noise, in addition to the indiscipline and flurry of people.

The Speed of vehicles is also identified as a major factor for noise. Analysis on different
types of two-wheelers, four-wheelers and types of fuels shows that noise level is almost
directly proportional to speed. Optimum speed derived for different types of vehicles
would prove advantageous in both ways, i.e. increasing fuel efficiency and reducing noise.
Noise level is also found to be increasing with the distance of the vehicle from the
intersection, i.e. noise is found increasing as the vehicle speed increases from the
intersection. With the increase of speed from the stop line at the intersection, noise level
enhanced by 5 to 8 dB by distance of 250 m. Factors responsible for this noise are found
to be engines, gears, tyre condition, and age of the vehicles, road type and condition.

From the 1/1 Frequency analysis it is found that in Ahmedabad noise frequency mostly
confined between 63 Hz to 2 KHz contributes the noise pollution predominantly. Peaks
can be seen in the low-frequency region between 63 and 125 hertz which is attributable
to the noise created by automobile engines. The honking response is predominantly
observed in the octaves of 500 Hz, to 2 kHz. Noise frequency corresponds to heavy

04