Santa Clara County, California

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Santa Clara County, California

latitude: 37.33, longitude: -121.94
Browse map of Santa Clara County 37°19′48.00″ N, 121°56′24.00″ W
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Santa Clara County is a county in California at latitude 37°19′48.00″ North, longitude 121°56′24.00″ West.

Santa Clara County is located at the southern end of California's San Francisco Bay Area. The county's urbanized area is known locally as the South Bay or Santa Clara Valley. The South Bay is known around the world as "Silicon Valley" due to its high concentration of silicon chip-making, software and high-technology companies headquartered in the area.

Santa Clara County includes the cities of Campbell, Cupertino, Gilroy, Los Altos, Los Altos Hills, Los Gatos, Milpitas, Monte Sereno, Morgan Hill, Mountain View, Palo Alto, San Jose, Santa Clara, Saratoga and Sunnyvale. As of 2019, Santa Clara County is the 18th most populous county in the U.S., and San José is the country's tenth most populous city.

State of the Map

OpenStreetMap's coverage of Santa Clara County has been improving for nearly two decades, yet remains a work in progress. The North County cities are exceptionally well-mapped in terms of infrastructure, addresses, and businesses. San Jose and West Valley have only minimal coverage of buildings and businesses and very few addresses. Cycling infrastructure is well-mapped, but many local and regional route=bicycle relations need completion with this infrastructure as member elements. The public bus transportation network (especially bus stops) is not especially well-mapped though rail infrastructure and passenger rail transportation might be called a rough-and-ready version 1.

San Jose ranks among the ten largest cities in the United States by population, yet San Jose's mapper community is smaller than those of other large cities, and its OSM coverage has a lot of room to grow. We need your help! Whether you prefer field surveying, armchair mapping, or finding freely-licensed data to import, you can help us build the best map of San Jose.

We're also mapping the history of the Santa Clara Valley in fine detail on OSM's sister project, OpenHistoricalMap.


The default aerial imagery layers in iD and Potlatch are of high resolution but date back several years, so check the vintage of an OSM feature before remapping it based on aerial imagery.

As of July 2017, the "DigitalGlobe Premium Imagery" layer is the freshest; however, it is quite severely offset. The "Mapbox Satellite" layer is slightly older but is better aligned. The "Bing aerial imagery" layer is several years outdated but very clear and well aligned. In general, you should trace over Bing or Mapbox imagery as a first pass, then double-check with DigitalGlobe to spot anything that needs to be updated.

Mapillary has thorough coverage of Sunnyvale, Santa Clara, and North and West San Jose. Elsewhere, it is largely limited to freeways, expressways, and some major arterial streets. OpenStreetCam has good coverage of Mountain View and better coverage than Mapillary of major arterial streets in other parts of the county.

The South Bay has several ethnic enclaves in which business names are posted exclusively in a language other than English. If you have difficulty reading the sign, upload a photo of it to Mapillary or OpenStreetCam for another mapper to enter into OSM. Alternatively, you can try to do it yourself by running the photo through optical character recognition, such as the OCR function built into the Google Translate application on Android and iOS. (Use only the OCR text, not the translation or transliteration.)

Works by county government agencies are in the public domain, per County of Santa Clara v. California First Amendment Coalition. County agencies such as VTA may have useful resources to aid in mapping. However, please observe the import guidelines before systematically entering external data.

Some useful Santa Clara County GIS layers to use as custom backgrounds in iD:

GIS layer Custom background URL template (iD) WMTS capabilities URL (JOSM)
Address points and parcels [1] [2]
City limits [3]
Points of interest [4]


Local user group
OSM South Bay Flag of the United States.svg
When: biweekly on Tuesday nights
Where: San José (map)
Mailing list
mailing list – archive
Open Source San José
National Day of Civic Hacking 2017, San José, California.jpeg

We held our first mapping party in Mountain View in Feburary 2009. Other mapping parties took place in 2009, 2010 and 2012 in San Jose. In 2015 and 2016, Maptime Silicon Valley organized annual map-related meetups at Stanford University. Since 2017, mappers have met biweekly to plan mapping projects together with the support of Open Source San José (formerly Code for San José). [5]

Find non-wiki-using mappers using Who's around me? Be sure to subscribe to the talk-us mailing list, where the broader U.S. mapping community discusses tagging, imports, policy, evangelization, and more. There's also a lower-volume talk-us-sfbay mailing list for more local discussion. If you have any questions, you can also ask on the #local-california channel of the OSMUS Slack workspace, the #proj-osm channel of the Open Source San José Slack workspace, or the #🗺openstreetmap channel of the Open Source San José Discord server. South Bay mappers are ready to help in any of these places.

Please introduce your friends to OpenStreetMap! Reach out to enthusiast communities in orienteering, urban planning, and open source. Show a local trivia buff the old_name=* tag; show a cycling enthusiast the cycling routes page.

Here are some articles community members have written about their experiences mapping in the South Bay:

Conference presentations:

Monthly OSM meetup minutes:



Santa Clara County has roadways rather unique in California known as "Expressways." Their history is curious: local citizens chartered them during the middle-20th century to be a three-phase tax approach to build freeways (highway=motorway). However, voters approved taxes for only the first two phases, leaving incomplete the final upgrade phase to freeway scheduled for the late-20th century. Expressways are usually dual-carriageway, moderate-to-higher speed roads (40-50 MPH or 65-80 km/hr) with traffic signals separated by relatively long distances. They are designed to minimize cross-traffic (few side-streets and driveways), have on-ramps, off-ramps, grade separated overpasses and underpasses in places, though mostly use highway=traffic_signals to regulate/route traffic, and so are denoted in OSM with highway=trunk. Only one has become a true freeway in California's legal sense (Guadalupe Parkway was upgraded to State Route 87, now highway=motorway). Different from freeways (which get a simple State Route number in their ref=* tag), these expressways are part of California's County Route system and get a ref=* tag beginning with one of nine region-based capital letters followed by a one- or two-digit number, e.g. "G6" or "G21." Whether by bicycle or automobile, expressways are aptly named, as they are often the fastest way to travel the traffic-congested roadways of Silicon Valley: many contain dedicated cycleway=lanes and "dynamic diamond lanes" with special overhead signals for high-occupancy vehicles (2 or more passengers) that change with daily commute patterns to keep traffic flowing.

Cycle routes

Main article: /Cycling routes

Public transportation

The county's public transportation networks vary in OSM coverage. National, regional, commuter, subway and light rail have good coverage, though most route=trains need upgrades to public transport version 2 to ensure software compatibility. Coverage of VTA's route=buses is poor and highway=bus_stops even poorer, though there have been efforts to import some VTA data. Each of the following pages catalogs either public transportation routes in OSM or an effort to improve or import into OSM public transportation data which serve Santa Clara County:


OSM in the wild

Some of our neighbors in Santa Clara County have recognized the care we've put into local coverage and have switched to OSM to take advantage of it:

To do

See also