The 15-30 minute city concept

 https://en.wikipedia.org/wiki/15-minute_city 

https://www.sciencedirect.com/science/article/pii/S2590198222000641

Ideally, if most things are within 15 minutes, that's great.

https://unfccc.int/news/the-15-minute-city 

https://www.deloitte.com/global/en/industries/government-public/perspectives/urban-future-with-a-purpose/15-minute-city.html

Even in the case of urban sprawl, a lot of things can be built within 15-30 minute town centers.

https://policyoptions.irpp.org/2024/10/15-minute-cities-canada

https://www.oecd.org/en/blogs/2025/04/from-the-15-minute-city-to-the-30-minute-region-rethinking-how-we-live-and-connect.html 

No matter how big a city or urban region is, 15-30 minute town centers can be built, but it can require a lot of work.

https://www.planetizen.com/news/2022/07/117975-could-la-be-15-minute-city

https://laist.com/brief/news/climate-environment/how-15-minute-cities-could-save-time-reduce-emissions-and-build-community 

However, sometimes people still have to get across town for various reasons. 

https://medium.com/sybarite/escape-to-a-15-minute-city-ce3707baf145 While its not impossible, to even establish 30 minute urban focal points in Greater L.A. can be challenging. If a person living in L.A. is within 15 minutes of walking or biking, or a bus or train trip from the stores and other services, that's great. However, a lot of people are still a 30-60 minute drive away from work & other places to get to. Thus, a 1 hour+ city is still unavoidable in some cases.

https://www.reddit.com/r/Urbanism/comments/1gtlylo/what_city_is_californias_best_option_for_a/