Just a thought, does your car warm up fully before you hit the traffic? If you were to drive a few miles at a steady speed before hitting the traffic, and your oil and water were at the proper temperature, then your economy would improve imensely. Also, if your car has a stop/start system, then your engine will turn off more often when its at temperature. Mine wont turn off automatically unless its fully warmed up.

NYC probably explains it all. That's a horrifically bad place for MPG.

Update.
Finally I did appointment today to local Nissan Service, but they refuse to take the car.
They told me, that is nothing we can do. They can’t diagnose the problem. But they understand that MPG I getting very low for this car. They told me to call to NISSAN and explain the problem.

Not very helpful of them. Have you had a chance to try any of the techniques mentioned above?

I still did not tried the car for long trip. Mostly City. I used gas - CITGO.
Next time I will switch for different brand. I think my driving technic is normal.
And again, I have Infinity G35 (6cyl) with the same driving condition in a city i got pretty much the same MPG, which I got with Rouge.

Keep in mind that in 2014, there were really TWO models Nissan called Rogue. The 2014 Rogue was different from the 2014 Rogue Select. Do you have the Select? If so, it has worse mileage as it's the older design.

No , I don't have Select.

I'd go take the car on a bit of a highway road trip and see how the economy stabilizes.

Don't speed. Smoothly roll on the throttle and smooth on the brakes, leave a following space in front of you to avoid jabbing the brakes all the time. Put the CVT in the "auto" mode (don't use "manual shift" if it has it, it's stupid on a CVT).

Since you have AWD it is the heavier one, keep in mind you are moving a 3600 lb hunk of metal around. Stop-and-go is terrible for it economy-wise. Boring, smooth driving is the key.

As for someone's suggestion of selling the car... I have a Subaru STi that only gets 18 MPG highway, $3600 in fuel in 24,000 km (15,000 miles). I'd take FAR more of a hit than that in depreciation getting rid of the car. Sometimes you just have to put up with bad economy.

Maybe pay attention to the automotive blogs talking about your car as well - they might issue a recall or software update to adjust engine computer or transmission behaviour at some later date to improve stuff.

I saw a 6mpg increase in mpg when driving on highway then just city. Plus your driving in NY so 15mpg is ok!!

0-40mph and stop and go traffic, 15-18MPG at best!!

I had a NISSAN Rouge loner car that was geting 22 mpg and I just hated driving that car becouse the car steering wheel was so sensitive with no feel so you may end up in a accident fast,I was happy when got my 02 nissan frontier back.