Living in San Mateo

Guides — Safety

Streets and safety

Which roads are hostile, where the freeway can be crossed, and what the city has and hasn't actually committed to.

Checked August 2026

Most of San Mateo is quiet residential street, and most trips here are uneventful. The exceptions are concentrated, predictable, and worth knowing before rather than after: two barriers, a handful of arterials, and a set of crossings that range from genuinely good to plainly unpleasant.

This page is about where those are. What the city should do about them is an argument, and this guide isn't the place for it.

What the city has on paper

San Mateo's street-planning record is muddled enough that it is worth knowing the shape of it before citing any of it.

The document that governs is the Strive San Mateo General Plan 2040, adopted by the City Council on March 18, 2024. A General Plan is the one instrument here that binds without qualification: it is adopted by ordinance, and other city plans and projects are meant to conform to it.

Underneath it sit a Bicycle Master Plan (2020) and a Pedestrian Master Plan (2012), which the city lists as its standing transportation documents. A citywide Complete Streets Plan was begun and is, by the city's own account, currently on hold.

The Sustainable Streets Plan of 2015 is the one to handle carefully. It is widely cited — by advocacy groups, by the transportation press, and in a great deal of secondhand writing since — as the moment San Mateo adopted Vision Zero and reformed how it evaluates street projects. The city's position is that the plan was never actually adopted, and contemporary accounts describe the Council accepting the document, which is a materially different act. Anyone intending to cite it at a public meeting should read the February 2015 minutes rather than the headlines written about them.

The distinction is not pedantry. An adopted plan constrains what staff can recommend; a received one is a study that sits on a shelf. It is also a useful early lesson in reading this city: the gap between what San Mateo is reported to have committed to and what it is actually bound by is wide enough to fall into.

US-101: the crossings

101 is eight lanes and it splits the city. Everything east of it — the flats, the lagoons, the shoreline — is reachable only at a crossing, and the crossings are not equivalent.

The useful ones inside the city are at Peninsula Avenue, 3rd Avenue, 19th Avenue, and Hillsdale Boulevard. Spacing is the real constraint: Hillsdale is roughly two miles from 19th Avenue to the north, and about two and a half from the Ralston Avenue bike and pedestrian bridge in Belmont to the south. If a crossing is closed or unpleasant, the detour is measured in miles, not blocks.

What makes one crossing better than another, in rough order of how much it matters:

  • Whether there is a sidewalk or path on both sides, or only one.
  • The angle of the on- and off-ramps, which determines whether a merging driver is looking toward where a person on foot would be.
  • Whether the ramp intersections have signals and marked crossings, or are free-flowing.

The 3rd Avenue and Norfolk Street intersection, at the western end of the 3rd Avenue overcrossing, was rebuilt with protected crosswalks and bicycle signals. The Peninsula Avenue interchange project proposes consolidating the southbound ramps and adding walking and biking improvements between North Humboldt Street and North Bayshore Boulevard. A separate Hillsdale pedestrian and bicycle bridge has been in planning for years. All three have project pages on the city site, which is where current status lives — these move on a schedule that outlasts any guide.

El Camino Real: the other barrier

El Camino is six lanes with a signal every block, and it runs the whole length of the city between the hills and the tracks. Nearly everyone here crosses it regularly, because the train, the groceries, and the good cheap food are on the far side from most of the housing.

Crossing it is a matter of using a signal, not of finding a gap. With a stroller or a child on a bike, the ninety seconds of waiting is the whole strategy. Mid-block crossings exist and are not where anyone should be teaching a kid to cross.

The state owns this road — it is State Route 82 — which is why improvements to it involve Caltrans and move slowly.

The other roads to respect

  • Delaware Street and North Humboldt Street are the north–south alternatives to El Camino east of the tracks, and both carry more speed than their residential frontage suggests.
  • SR-92 through the middle of the city is a freeway with surface-street intersections at either end, and the transitions are where people get caught out.
  • Alameda de las Pulgas is pleasant and popular with cyclists, and has stretches with no shoulder and a lot of curve.
  • The hill streets west of the Alameda frequently have no sidewalk at all. Walking there means walking in the roadway, which residents do constantly and visitors find alarming.

What is being built

The city's active walking and biking projects are the most concrete answer to what the streets will be like in five years. As of this writing they include separated bike lanes at 19th Avenue and Fashion Island Boulevard, the Delaware Street Safe Routes to School improvements, and separated lanes on 28th Avenue serving bicycle access to the Hillsdale Caltrain station.

An existing 2.1-mile bike lane on North Humboldt Street and Poplar Avenue has been the subject of a removal debate, which is a reminder that installed infrastructure here is not permanent by default.

Project status, funding, and construction dates all change. The city's Public Works project pages are the source; Move San Mateo tracks the walking and biking ones and is faster to read.

Reporting something

Potholes, broken signals, burnt-out streetlights, faded crosswalks, and blocked sidewalks go to the city's service request system, which is reachable from cityofsanmateo.org and has a phone option. Requests are tracked and do get closed out.

A dangerous location is a different kind of report, and the venue for it is the record — a service request, a comment at a Council or commission meeting, or an email to the council member for the district. See showing up for how those work.