Santa Clara County, California
|Santa Clara County, California|
|latitude: 37.33, longitude: -121.94|
|Browse map of Santa Clara County 37°19′48″ N, 121°56′24″ W|
|Use this template for your city|
Santa Clara County is a county in California at latitude 37°19′48″ North, longitude 121°56′24″ 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. It 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. 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.
State of the Map
OpenStreetMap's coverage of Santa Clara County has been improving for over ten years, 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 could use more completion of local and regional cycling routes on many route relations. The public 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 and OSM coverage can be described as only moderately developed. 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.
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 The "Bing aerial imagery" layer is several years outdated but very clear and well aligned.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.
We held our first mapping party in Mountain View in Feburary 2009. Since 2015, Maptime Silicon Valley has organized annual map-related meetups at Stanford University. As of 2017, Code for San Jose (the local chapter of Code for America) is helping to plan a mapping party as part of an effort to organize a South Bay mapping community. 
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. If you have any questions, you can also ask on the U.S. community's Slack channels, where you might encounter a South Bay mapper happy to help.
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.
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 / 65-80 kph) 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). Different from freeways (which get a simple State Route number in their ref=* tag), 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.
Main article: /Cycling routes
The county's public transportation systems have varying levels of coverage in OSM. Commuter and light rail has good coverage, though much of it needs to be upgraded to the new public transport to ensure software compatibility. Coverage of VTA bus routes is poor and VTA bus stops even poorer. Each of the following pages catalogs public transportation routes in OSM or an effort to improve or import into OSM public transportation data which serve Santa Clara County:
- Altamont Corridor Express
- Bay Area Rapid Transit (BART)
- Santa Clara Valley Transportation Authority (VTA)
The VTA Trip Planner is powered by OpenStreetMap cycling infrastructure data.
- Break up landuse=* areas into smaller, logical, named areas. For example, use landuse=residential for individual residential subdivisions, landuse=retail for retail complexes like strip malls, and landuse=commercial for office parks.
- Add maxspeed=* , maxspeed:advisory=*, maxheight=*, and maxweight=*.
- Add lanes=* tags to major thoroughfares. 
- Replace note:lanes=left lane is hov  and note:lanes=right lane is hov  with the appropriate hov:lanes=* tag.
- Add destination=* and destination:ref=* to link ways (freeway on-ramps and off-ramps alike) (see Exit Info).
- Add more San Jose neighborhoods as place=suburb or place=neighbourhood POIs.
- Micromap school grounds.
- Add crosswalks, especially at signalized intersections, which may require moving highway=traffic_signals points from the stop line to the middle of the intersection.
- Replace disconnected highway=stopline ways added by pflier with road_marking=solid_stop_line nodes on the associated ways.
- Add ramp meters as highway=traffic_signals traffic_signals=ramp_meter.
- Code for San Jose wishlist