Hi, is this line correct?

'In the morning in this city, people spend hours and hours in traffic bumper-to-bumper.'

My question is three.

1, Which is correct or bettter to use among 'in ','of ' and 'at'?

2, Is comma necessary after city?

3, Is bumper-to-bumper in the right position?

Please help me out.
1. "In" is correct.

2. Yes, you must use the comma after city.

3. The expression is "bumper-to-bumper traffic".

Each morning, in this city, people spend hours and hours in bumper-to-bumper traffic.

- Arvin G.
For me it would sound better like:
During the morning in this city people spend hours and hours in a bumper-to-bumper traffic.

I'm not sure about bumper-to-bumper, I'd use it as an adjective, but:
1) I'd rather change the first "in" instead of the second one to avoid the repetition
2) for me the comma is not needed
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Hi, Arvsworld.

Hi, Zeppe.

Your opinions really helped me!