Traffic Couint data by intersection. The County of Los Angeles conducts over 1600 vehicular traffic volume counts per year. The data is a compilation of Average Daily Traffic (ADT) gathered largely from the unincorporated areas of the County of Los Angeles. The data includes the location, count date, 24-hour ADT, AM Peak, and PM Peak.

Mile markers are generally located along the road side edge where a culvert passes under the road. The Malibu area, Road Maintenance District 336 and 339, the mile marker positions were located at the inlet and outlet of the drainage asset, so they may not be right along the road's edge. Remaining mile marker positions throughout the County were located by a vehicle mounted receiver/antenna stopping near the mile marker within less than 5 feet of the marker post. Expected accuracy of all positions is less than one meter, but data position is not exactly at the marker post. With few exeception in Districts 336 and 339, most positions are within 10 to 20 feet of the actual marker post and along the road side edge.

2010 Census Blocks clipped to the County Boundary. A new field “COMMNAME” was added and populated with city and community names based on 2011 redistricting unit community names in the census block data.

2010 Census Tracts clipped to the County Boundary. Two new fields were added to this census tract data – area in square feet and area in square miles.

City boundaries managed by the LA County Dept. of Public Works. Unincorporated areas are not distinguished by name, other than labeled unincorporated.

ZIP Codes in Los Angeles County.

ZIP codes are a system of postal codes used by the United States Postal Service (USPS) since 1963. Provided here because many tables and other datasets have ZIP code information within them. Managed by the USPS but provided for reference purposes.