I'd love to see cities put efforts into connecting those isolated cultures-de-sac neighborhoods with pedestrian and bike paths.

I can understand the desire to reduce through-traffic which sometimes comes with speeding or aggressive drivers. But walking and cycling to your friends house shouldn't mean going a mile out to the entrance of your neighborhood, down the busy highway, then a mile back in to their house when they were only half a mile away to begin with.

My neighborhood was platted in the late 50s, and it has what the kids call "secret sidewalks" that cut between the houses and connect the streets. It's the best of both worlds: Minimal car traffic, but easy to get around by walking. The secret sidewalks also radiate outward from the elementary school, approximately.

Cities charge a right-of-way fee, planning, and permitting process every time you connect to a public road. The county/city planning committee often requires new neighborhoods to cover the cost (often via HOA) of roads and their easements in the neighborhood. The end result is the neighborhood private planners have their hand forced to eliminate thru-traffic and minimize connections to arterials.

The county would basically have to do the opposite to change things; provide low-cost/low-overhead process for connecting to public road and pay neighborhoods/HOA for connecting to arterials to offload the traffick and provide thru-routes. Otherwise the public is just leaching off the private roads, and due to neighborhood planning requirements they usually can't charge a toll to get it back, so it gets designed to avoid that.

I don’t like cul-de-sacs in general but they can be walkable if there are shortcuts for pedestrians/cyclists and only cars has to follow a long way. You also need amenities in a walking distance. One can find such neighbourhoods in the UK.