Greetings trofimus,
What about trains? And buses? Will there be taxi drivers?
There will be no need for trains, buses and taxis! Remember, at that time believers will all be in their immortal and glorified bodies. These bodies that were sown in weakness will be raised and changed to have power. We will not be restricted to walking, but will most likely be able to travel at will.
The new Jerusalem is a real city that God is preparing for the faithful. As Snoozy pointed out, the dimensions and characteristics of the city are very detailed, which would not lend to a symbolic interpretation. There are twelve gates each made from a single pearl with an angel at each gate. The width, depth and height are the same being 1500 miles. The wall of the city is 200 ft. thick. And the river of life will be running down the middle of the city. Paul mentions the city in reference to the hero's of faith"
"All these people were still living by faith when they died. They did not receive the things promised; they only saw them and welcomed them from a distance, admitting that they were foreigners and strangers on earth. People who say such things show that they are looking for a country of their own. If they had been thinking of the country they had left, they would have had opportunity to return.
Instead, they were longing for a better country—a heavenly one. Therefore God is not ashamed to be called their God,
for he has prepared a city for them.
Jesus refers to the New Jerusalem as a real city:
" I will write on them the name of my God and the name of the city of my God, the new Jerusalem, which is coming down out of heaven from my God; and I will also write on them my new name."
At the end of Revelation there is a warning for those who add to or take away from the book of Revelation. For those who take away, he will take away that persons share in the tree of life and the new Jerusalem:
" And if anyone takes words away from this scroll of prophecy, God will take away from that person any share in the tree of life and in the Holy City, which are described in this scroll."
When you have something mentioned consistently in scripture, it is a good indication that it is meant to be interpreted in the literal sense.