You can poll people about things that they want, but (like it happened with many great inventions) people don't actually know what they need. Do they want less car-centric environment? Most will answer "no" because they've never lived in a society that wasn't as car-centric. Most people are not urbanists and most are content with their lives. You can poll them and do inquiries to death, or you can allow experts to implement all of the things that are unambiguously good from any perspective, let people grumble for a bit, adjust and after that reap benefits.
A part of being a democratic society is accepting that an opinion of an average person is worthless.
A part of being a democratic society is accepting that an opinion of an average person is worthless.