Lawsuits challenge how San Diego, San Francisco and Montebello interpret SB 79
Lawsuits in San Diego, San Francisco and Montebello challenge how cities interpret train frequency counts and sidewalk gap exemptions under California's 2026 transit housing law.
SB 79, signed in October 2025 and effective July 2026, allows taller, denser housing near qualifying transit stops across eight California counties. But San Diego, San Francisco, Montebello and the San Diego Association of Governments (SANDAG) are now facing lawsuits alleging they used exemptions and misinterpretations to exclude parcels from the law's density mandates. The disputes center on how to count train frequency and whether minor sidewalk gaps should disqualify sites with clear walkable access to transit.
These lawsuits matter for property owners, developers and buyers because they could force cities to rezone parcels currently outside SB 79's density boost. They also signal how much room exists for local interpretation in a state law designed to unlock housing near transit.
What SB 79 does
SB 79 authorizes apartment construction near transit by establishing two density tiers. Tier 1 sites (within a half-mile of stations with 72 or more daily trains) can go as tall as 95 feet. Tier 2 sites (within a half-mile of stations with 48 to 71 daily trains) cap out around 85 feet. The law applies to residential, mixed-use and commercial zones in eight counties with substantial rail infrastructure, affecting less than 1 percent of transit stops statewide.
Height allowances taper closer to stations. Near Tier 1 transit, buildings can reach nine stories immediately adjacent, seven stories within a quarter-mile, and six stories within a half-mile. Tier 2 sites allow eight stories adjacent, six within a quarter-mile, and five within a half-mile.
The law requires between 7 and 13 percent of units in new projects to be affordable, with the required share depending on the depth of affordability.
How train frequency disputes reshape zoning maps
The most legally complex question is how to count trains. State guidance says agencies must combine all rail lines serving a single station to reach the daily trip threshold. But cities and transit operators interpret this guidance differently.
In San Diego County, the Oceanside Transit Center serves four separate operators: the Sprinter, Coaster, Pacific Surfliner, and Metrolink. YIMBY Democrats of San Diego County calculated approximately 130 weekday trips across all four lines, which would qualify the station for Tier 1 density (72+ trains daily). But SANDAG, the regional planning agency, counted the rail lines serving the station separately rather than combining them, arriving at "more than 48 but fewer than 71" trains per day—placing it in Tier 2, which allows less density.
Solana Beach Station presents a starker case. The station serves two operators totaling roughly 56 weekday trips: 30 Coaster trains and 26 Pacific Surfliner trains. That combined count clears Tier 2's 48-train threshold. But SANDAG's map excluded Solana Beach from both tiers entirely, meaning SB 79 density rules do not apply there.
SANDAG says its methodology follows the statute more closely than nonbinding state housing department guidance. But the housing groups argue the law and guidance both require combining all services at each station. If courts side with the housing groups, SANDAG's map could be redrawn to include parcels currently zoned for lower density.
Sidewalk gaps become a loophole
SB 79 allows cities to exempt sites from density requirements only if "there exists no walking path of less than one mile from that location to the transit-oriented development stop." The threshold is strict: according to the lawsuits, a gap in sidewalk coverage should not by itself trigger an exemption when a walkable route otherwise exists.
Yet some cities interpret the rule expansively. In San Diego, a property 375 feet from a trolley station was removed from SB 79 density maps because of a 100-foot gap in formal sidewalk coverage along a paved alley. The property had clear visibility and safe access to transit despite the missing section. Plaintiffs argue this reading eviscerates the statute: minor gaps in sidewalk coverage should not disqualify parcels where pedestrians can safely walk to stations.
The sidewalk exemption dispute matters because cities control what counts as a "walking path." Disagreement over whether features like alleys meet pedestrian standards will determine which sites fall under higher density rules. Cities with strict interpretations can exclude large swaths of parcels near transit.
“If courts side with the housing groups, SANDAG's map could be redrawn to include parcels currently zoned for lower density.”
How San Francisco and Montebello deploy different avoidance strategies
San Francisco faces a different allegation: the city created three "industrial employment hubs" to circumvent SB 79. These zones allow housing but remain outside the law's density mandates—a workaround that lets San Francisco claim compliance while denying the density increases the law envisions. The housing groups further allege San Francisco then blocked these parcels from benefiting under California's density bonus law, another state statute that increases allowable density on sites with affordable housing.
Montebello's lawsuit alleges a city council moratorium on SB 79 projects in parts of town violates both SB 79 and California law that prohibits housing moratoriums. State law requires cities to process housing applications on time; a blanket pause on SB 79 projects would breach that duty. The Montebello case may be the most straightforward—whether a city can simply pause projects on qualifying sites—but it signals plaintiffs' willingness to challenge multiple violation theories.
What resolution could mean
If courts accept the housing groups' positions, cities would face redrawing implementation maps to include disputed parcels, removing improper exemptions, and opening sites for development at higher densities. Developers would gain access to zoning allowing taller buildings in areas currently off-limits. Property owners sitting on parcels excluded from SB 79 might see their land reclassified as developable at higher density, increasing its value.
Cities that lose these cases face a choice: accept denser development near transit or defend their interpretations further. The disputes reveal a consistent pattern: where state law creates clear housing opportunity, local interpretation can narrow or block it. SB 79's success depends on implementation. These lawsuits test whether the law's intent survives contact with local zoning machinery.
Related coverage: SB 79 and the end of low-density zoning near California's transit stops; What an ADU can and cannot be in California.
