There is a superstition in Mumbai of Indiathe Indian city of Mumbai that honking makes thea red light of the traffic slignalht change to the green light faster.

We usually just say "red light" or "green light", and these refer to traffic signals if there is some context to the conversation. But in this case, since this sentence is the start of your writing, we can specify it by saying just "red traffic light".

Drivers have to wait 90 seconds for the light to turn green.

Your original was technically correct, but this is a more natural way to say it.

There is a second clock byclock beside the signal and the time shows ina countdown style, like 89, 88, 87 towarduntil it hits 0.

"Second clock" doesn't make sense because it sounds like it's there along with a "first clock", but you haven't mentioned what the "first clock" is. Maybe you meant secondary or "extra" clock, but those aren't needed here since you haven't even mentioned a "clock" yet in your writing.

The police attached a noise level meter under the second clock to improvedo something about this large amount of noise.

I changed this to be more natural based on your original Japanese. Also, I say "large amount of noise" here because: a "large noise" feels like "a single, loud noise", but a large amount of noise is many things making noise for a long period of time. This makes more sense for "many cars honking at the traffic signal".

While the clock was showinged the time in countdown, when the noise level reached 85 decibels, the time wentreturned back to 90 seconds as the initial value of 90 seconds.

AndThen the countdown started again.

Many drivers got angry and the police officers were doing a high -five withing each other.

The hyphen "-" here may be optional. Even natives will argue about this small detail :)

But I figured out that irealized that, if the police went to such extreme measures, the problem must hadve been difficult to improve it so far as to do such a thing.

Reworded to be more natural. "Figure out" sounds like you read the news article with the objective of discovering something hidden or difficult to understand, but "realize" sounds like you just found some knowledge while reading.

There is a superstition in Mumbai of, India that honking makes the red light of the traffic signal change to the green light faster.

There is a second clock byclock next to the signal and the time shows ina countdown style, like 89, 88, 87 towards 0.

The drivers can see how many seconds they willhave to wait, yebut they start toill honk all at once when the singnal turns red.

The police attached a noise level meter under the second clock to improve this largcounteract the noise.

While the clock was showing the time in counting down, whenif the noise level reached 85 decibel, then the time went backould return to 90 seconds as the initial valuend start again.

And tThe countdown started againwould restart repeatedly.

MEven though, many drivers got angry and the police officers were doing aould high five with each other.

But I figured out that it had been difficult to improve it so far as to do such a thingI thought it is difficult to improve the traffic light situation.

There is a superstition in Mumbai ofin India that honking makes the red light of the traffic signal change to the green light fast.

Drivers have to wait 90 seconds for the green light.

There is a seconds clock by the signal and the time shows in countdown style like 89, 88, 87 towards 0.

The police attached a noise level meter under the seconds clock to improve this largedecrease the amount of noise.

While the clock was showing the time in countdown, when the noise level reached 85 decibels, the time went back to 90 seconds as the initial value.

Many drivers got angry and the police officers were doinggave each other a high -five with each other.