You're looking for what is known as "the green book" published by aashto Geometric Design of Highways and Streets https://aashtojournal.org/2018/09/28/aashto-

You're looking for what is known as "the green book" published by aashto Geometric Design of Highways and Streets https://aashtojournal.org/2018/09/28/aashto-releases-7th-edition-of-its-highway-street-design-green-book/ https://aashtojournal.org/2018/09/28/aashto-releases-7th-edi... But this comes after the traffic and environmental and planning studies, so it's more of a "how" to build, after you've at least gone through some preliminary design and figured out "what" to build. And yes, there is literally a table (for highways at least) that gives values for lane width vs the "natural speed" that drivers gravitate to.