Fill That Train

People within a half mile

This is the metric for successful transit — roughly 30,000 people within ½ mile. Almost everyone who rides rail walks to the station. That walk is about ½ mile — 800 m, or ten minutes. Past that, people drive. A station works if enough people live in that circle. A city’s total population, or a line that runs through empty land, does not.

Canada made this the legal test. Ontario must draw each Major Transit Station Area at 500–800 m and “maximize the number of potential transit users that are within walking distance.” The federal Public Transit Fund ties capital for cities over 150,000 to high-density housing and no parking minimums inside 800 m of higher-order transit. BC requires extra height out to 800 m of SkyTrain. If the people are not in the walkshed, the station is not succeeding on those terms.

That same ring is the global default. New Zealand requires at least six storeys in an 800 m walk of rapid transit. The ITDP TOD Standard scores development within 500–1,000 m of rapid transit. US rail research uses ½ mile because density there predicts ridership.

Green meets 30,000 people; red is short. Turn systems on or off on the map. Click a station for the count.

Each station

SB 50

SB 50 was California’s effort to be like Canada, New Zealand, and much of the rest of the world: legalize apartments in the walkshed so these stations could fill. ½ mile of rail or ferry, ¼ mile of a frequent bus, and in job-rich neighborhoods. No density cap. Height floors of 55 feet near rail, 45 feet out to ½ mile. Parking waived. Ontario and New Zealand do this as law. It did not set a people number. SB 827 tried this first, in 2018, and died in committee.

Here is how people voted. The Senate killed it January 30, 2020. 18 yes, 15 no, 6 did not vote. It needed 21. Democrats held the chamber. Both parties voted no: 11 Democrats and 4 Republicans against, plus 3 of each who did not vote. Three Republicans voted yes. District 28 was vacant. Green voted yes. Red voted no. Light red did not vote — a soft no. Click a district for the senator. These are the 2011 lines, the map in force that day.

The main argument was local control. Cities, through the League of California Cities, said the state should not override zoning, especially in single-family neighborhoods. Sen. Anthony Portantino held the bill in committee in 2019 on that ground. On the floor, Sen. Bob Hertzberg said it wrongly blamed cities and homeowners. Sen. Jerry Hill wanted cities to pick the sites, and to keep parking. Sen. Steve Glazer said his cities had already approved units that were not being built. The split was geographic, not party. Suburban and coastal Democrats voted no with most Republicans.

A second group, mostly Los Angeles Democrats, said the bill would not produce enough affordable housing and would speed gentrification. Sen. Maria Elena Durazo voted no on those terms. Tenant groups made the same argument. Wiener had already added set-asides and anti-demolition rules. Nine Los Angeles–area senators voted no or did not vote; one voted yes. In the Bay Area the no votes were the Peninsula, the East Bay suburbs, and Napa.

What California is doing

California has passed laws that name this ½ mile. It has not set a people target. Some rewrite the circle. Others add density on a project zoning already allows. SB 827 and SB 50 tried the whole walkshed, like Canada and New Zealand. They did not pass. SB 79 is the current compromise.

What SB 79 does and does not do

SB 79 is the current compromise. It makes housing an allowed use on lots already zoned for housing or shops, near a qualifying rail or BRT stop, in a county with more than 15 passenger rail stations. As of July 1, 2026 that is Alameda, Los Angeles, Sacramento, San Francisco, San Mateo, Santa Clara, and San Diego. Incorporated cities apply now. Unincorporated land waits until the 7th housing-element cycle. Orange may join when the OC Streetcar opens.

Near BART or Caltrain: 120 homes per acre and 75 feet within ¼ mile; 100 and 65 feet out to ½ mile in cities over 35,000. If the whole ½-mile circle were housing at those floors, about 53,000 homes, or about 130,000 people at 2.5 per home. Light rail, Muni Metro, VTA, and BRT: 100 homes per acre and 65 feet; then 80 and 55 feet — about 43,000 homes, or about 110,000 people. That is a zoning envelope, not a people target. No ministerial permit of its own. Cities can defer or write an alternative plan.

Green applies. Gold is pending. Gray is out. Hover a county for its passenger rail stations — more than 15 to qualify. One location counts once. Planned stops and BRT do not. Compiled counts, not an HCD roster.

Ontario treats the ½ mile as a place that has to fill: draw each station area at 500–800 m, and hit 150 residents and jobs per hectare on commuter rail — about 30,000 in this circle. SB 79 never asks whether the circle filled.

Most red stations on this map will stay red through this decade. The law is months old. Filings — 341 homes in Palo Alto, 20 in San Mateo, 30 in Atherton — are applications. AB 2011 took three years to put 800 homes under permit. Cities can defer. Stations the law skips, and stations with a freeway in the circle, do not get this tool.

What cities are doing

A city can defer lots already zoned to half the state floors, write an alternative plan, or exempt industrial hubs. Los Angeles, San Francisco, and San Diego used those options. Sacramento and Berkeley did not. There is no official list of projects. HCD reviews city ordinances, not buildings. An unofficial project tracker exists.

The named applications so far are in smaller cities: nine Palo Alto pre-apps for 341 homes, then a city deferral; 20 homes in San Mateo; 30 in Atherton; five townhomes in Santa Monica; 171 in South Pasadena, after which that city deferred downtown. None are under construction.

Highway caps

Zoning only works on land that can take a building. A freeway through the ½ mile has no residents. Cities have put a lid on the road: parks, streets, and housing on the roof, or towers on air rights over the lanes. That empty pavement is already inside the circle. A cap can put people there.

Other cities

A ½-mile / 800 m circle is about 201 hectares. This page uses the median stop on each system. The other cities apply a published station-area or city density to that same circle, so the unit matches. Typical, not every stop.

Why half a mile

The sources behind that ½-mile / 800 m walkshed. ACS 2024 block groups — a group counts if its center is inside. Overlapping stations share some of the same people.

Why 30,000

This page uses 30,000 people within that ½ mile as the bar. A ½-mile circle is about 201 hectares. That figure is Ontario’s commuter-rail planning density (150 residents and jobs per hectare in an 800 m walkshed), counted here as people. Ontario’s subway target is higher. Canada’s federal rule and BC’s SkyTrain law set zoning, not a headcount. The US research numbers are lower. Massachusetts requires a multifamily district in the same ½ mile, but the floor is 15 homes per acre. Muni stops follow the SFMTA Rapid Network: J, K, L, M, N, T, 5R, 9R, 14R, 28R, and 38R.