'friendly cities' is a correct and usable phrase in written English.
For example, you could use it in the sentence, "Portland is one of the most friendly cities in America."
Washington also happens to be one of the most gay friendly cities in the United States.
A Vancouver official told The Oregonian that it was "the ultimate in bicycle stations", and would be natural for bicycle friendly cities to emulate.
These and some other improvements became possible thanks to UNICEF's Child Friendly Cities Initiative (CFC).
The 13 regencies awarded are areas that have specific policies and programmes that supports child friendly cities.
The Child Friendly Cities Initiative (Word) (PDF) A progress report on the initiative for a child friendly Bam.
In the Philippines, the Child Friendly Cities Initiative emerges as a good practice in dealing with urban challenges.
Age-friendly cities need to be smart cities.
Which are the most cycle-friendly cities in the world?
Right away, liberal mayors insisted the poultry outfit avoid their gay-friendly cities.
Portland is nationally recognized as a leader in the movement to create bicycle-friendly cities.
This is, after all, one of America's least union-friendly cities.
