Tons of them. Besides mixed-use zoning bans, there’s a widespread problem of regulation on everything from road widths to sidewalks to house and lot dimensions, setback requirements, lawn sizes, fencing, 2-way street requirements. All this stuff combines to reduce density and make older style high density single-family and multi-family mixed neighbourhoods impossible.

Remove mixed use restrictions. So store fronts can have residential above. Remove medium density restrictions. Tax credits should for new housing should include, if not favor, condos over rentals and single family homes.

Schools until at least highschool should have to be within a 15 minute bike ride/walk for students homes of a district.

Street parking should have to be heavily justified, and assumed no. That space would be better served with green spacers and bike/side walks. For areas with high density parking garages that are linked to their public transport would go a long way. Intercity rail makes a lot of sense in the midwest, so much sense that used to be the norm!

Mandatory parking minimums

One of the most impactful thing you can do is vote locally for candidates that support transit and density.

It's not just lack of mixed-use zoning; it's lack of dense zoning. On average, something like 75% of the residential land area in US cities are zoned for single-family houses only. Moreover, not all single-family zoning is created equal: for example, in my city most of the neighborhoods are "R4," which means minimum lot sizes of 9000 sq. ft. (roughly 0.2 acres), but the category with the largest lots, "R1," requires a minimum of 2 acres. Even just rezoning the mansions in the fancy neighborhoods from R1 to R4 would basically 10x the density, let alone developing them to their highest and best use (i.e., multifamily, which would easily 10x it again, if not more).

Every urban single-family house on a modest lot physically displaces 10 families further out into the suburbs. Every urban mansion on a large lot physically displaces 100 families further out into the suburbs.

And you know what adds insult to injury? The owners of these properties are not paying 10x or 100x what people who own units of dense housing are paying -- not even close. Because the zoning prohibits developing to the highest and best use, it devalues urban lots compared to what they should be worth, and thus gives those homeowners a massive subsidy on their taxes! [Insert rant about how Georgism is better here] Urban homeowners are generally likely to be wealthier than renters, and the larger the lot they own, the more wealthy they're likely to be. So now our subsidy that's already unjust is regressive on top of everything else, subsidizing more the wealthier the homeowner is!

Frankly, people need to understand this and get fucking mad about it, because it's a goddamn unjust outrage just on grounds of equity, even before you get to the urbanism/walkability part!

Repeal Jaywalking laws.

The laws will differ from state to state and even between cities within the same state. The fundamental change has to be concentrating population in a given metro area, which will increase business opportunity in the area where population increases.

Land Value Tax.

It’s not. Zoning is the problem but also the solution. Definitely mixed use, definitely high density.

I like the variation “transit oriented development “. Build a train system as your focus. Actively guide development around each station. Zone for mixed use and higher density, but needs active encouragement, needs to smooth out the requirements. In the Boston area, one of the keys is higher density “by right”. Typically bigger buildings are treated case by case by zoning boards but that’s paperwork, delay, discouragement. “By right” says those are approved by default in that zone, just like a single family home in a zoned residential: less bureaucracy less paperwork, less delay

I call it "the cartwheel test".

Basically if you can do 50 cartwheels, and haven't passed anything useful yet, it's not a walkable city.

Maybe a school. Maybe a CVS/Walgreens. Maybe a laundromat. Maybe a movie theater. Maybe a tax place. Maybe a seniors center. Maybe a daycare.

Just anything that SOMEONE is going to find useful.