CAMS Data (October 2011)
Current data date: August 2012 – we will be releasing new versions of this data periodically.
Important note: This file is not final – it is an intermediate step and should be used with the understanding that further work is being performed.
Description
The LA County Street Center TIGER road file is a street centerline network in development by Los Angeles County to move toward a public domain street centerline and addess file. This dataset can be used for two purposes:
- Geocoding addresses in LA County – this file currently geocodes > 99.5% of the addresses in our test files (5,000 out of 8 million addresses) using the County’s geocoding engines.
- This last statement is important - the County splits the street names and addresses differently than most geocoders. This means that you cannot just use this dataset with the standard ESRI geocoding (US Streets) geocoding engine. You can standardize the data to resolve this, and we will be publishing the related geocoding rules and engines along with instructions on how to use them, in the near future. Please review the data fields to understand this information.
- Mapping street centerlines in LA County – note that the street types in this file are not fully updated yet. Use with caution.
- Routing and network analysis
- Jurisdiction and pavement management
History
LA County has historically licensed the Thomas Brothers Street Centerline file, and over the past 10 years has made close to 50,000 changes to that file. In order to provide better opportunities for collaboration and sharing among government entities in LA County, we have embarked upon an ambitious project to leverage the 2010 TIGER roads file as provided by the Census Bureau and upgrade it to the same spatial and attribute accuracy as the current files we use. This effort is part of the Countywide Address Management System (click the link for details).
Processes
The County downloaded and evaluated the 2010 TIGER file (more information on that file, including download, is at this link). The evaluation showed that the TIGER road file was the best candidate to serve as a starting point for our transition.
Since that time, the County is moving down a path toward a complete transition to an updated version of that file. Here are the steps that have been completed and are anticipated.
- Upgrade the geocoding accuracy to meet the current LA County street file licensed from Thomas Brothers. This has been completed by the Registrar/Recorder (RRCC) – matching rate have improved dramatically. COMPLETE
- Develop a countywide street type code to reflect various street types we use. We have used various sources, including the Census CFCC and MTFCC codes to develop this coding. The final draft is here – Final Draft of Street Type Codes for CAMS (excel file)
- Update the street type information to support high-quality cartography. IN PROGRESS - we have completed an automated assignment for this, but RRCC will be manually checking all street segments in the County to confirm.
- Load this dataset into our currrent management system and begin continuing maintenance.
- Data download in ArcGIS 10 File Geodatabase format – 116 Mb - (CAMS_2011_1024.zip)
- Data download in Shaepfile Format – 66 MB - CAMS_2011_1024 (zipped shapefile with layer file)
- New – updated data as of August 2012 - CAMS_2012_08 (zipped shapefile)
- Related layer file for quick symbolization: CAMS_2011_1024 - Note that this is a very schematic and not very cartographic representation, but should give you some idea on how to use it.
You are exactly right.
Hi Mark,
A question for this line data with some fields in pairs (Left and Right)–Do you think we could assume the Left field as start points, and the Right field as end points, when calculating the X,Y coordinates for Left/Right of this line data?
Thanks,
Waley