UPDATE
Geocoded SWITRS data is now provided through the City of Los Angeles Geohub. You can search for SWITRS to find the latest available data at: http://geohub.lacity.org/datasets?q=switrs
The data originally linked on this blog post below is no longer updated.
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On the heels of releasing the HSIP Helper a few weeks ago, we are now providing a full set of geocoded SWITRS data for the City of Los Angeles to planners, engineers, researchers, or anyone working with collision data in Los Angeles. While many of you have utilized the great service provided through TIMS at UC Berkeley, you may have realized there are several geocoding deficiencies with Los Angeles data once you started to dig a little deeper. To address those issues it requires giving specific attention to problematic locations and we at RoadSafe GIS have done this to build a better system for Los Angeles.
Through this exercise we have also been able to validate our own geocoding processes and the usability of our RoadSafe GIS collision data management system. Approximately 93% of the collisions have been geocoded and errors have been minimized via thorough manual reviews. During our work, we realized this data would invaluable for users in Los Angeles and wanted to make it available for free to everyone even without a subscription to RoadSafe GIS. This data can be used to help prepare grant applications for the HSIP program or the California Active Transportation Program Cycle 2.
Our experience geocoding the data will also provide material for a series of blog posts describing the types of issues encountered and how they were resolved. Our introduction to that series was just posted here. So if you are interested in the specifics, keep an eye out for the rest of the series.
“Ok, ok, so where’s the data?” Without further ado the data is available below.
What the data contains:
- Geocoded SWITRS data from 2003 to 2012 for all crash severity levels, including Property Damage Only (PDO) collisions. Also included is a provisional version of 2013 and 2014 data that was released as of late January 2015. The provisional versions may still be updated and more records will be added. 2013 data appears to be about 90% complete and 2014 data about 50% complete. We will provide updated versions of both years when 2013 data is finalized.
- All collisions on non-state highways marked in SWITRS as occurring in LA City jurisdiction
- Collisions on state highways where all or a portion of the highway is a surface street:
- State highways 42, 213, 1, 27 (and the intersection of Ferry@Seaside and Navy@Seaside on SR 47)
- State highway 110 – All between postmile values 0 and .745
- State highway 170 – All between postmile values 9 and 10.61
- State highway 2– All postmile values below 14.08 (Glendale Fwy begins)
- Collisions at ramp intersections with local roads. In some cases it can be difficult to distinguish an intersection with a local road or another ramp segment. However, all the collisions with these ramp values are included:
- 1 – Ramp Exit, Last 50 Feet
- 3 – Ramp Entry, First 50 Feet
- 4 – Not State Highway, Ramp-related, Within 100 Feet
- 5 – Intersection
- 6 – Not State Highway, Intersection-related, Within 250 Feet
- Additional fields in the collision data table for a standardized matching address (match_addr), primary road name (m_primaryr), secondary road name (m_secondrd). These are very useful fields for ranking by intersections. RoadSafe GIS utilizes these fields for generating rankings by various safety performance functions.
- Party and victim data tables that correspond to the SWITRS collision file.
UPDATE: 7/29/2015
A new download has been provided with updated 2013 and 2014 SWITRS data. This data was retrieved from ISWITRS on July 21st, 2015. There were an additional 288 records added for the 2013 dataset. The 2013 dataset appears essentially complete, but CHP has not yet published their final 2013 report. The 2014 dataset now appears over 95% complete, but records will still be updated, especially for highway ramp intersection collisions.
Note that the field names have been updated to reflect the original headers provided by CHP in addition to our several added fields. You can access their raw data template here.
UPDATE: 8/17/2015
Approximately 1,000 records coordinates were updated. No other changes were made.
Download a file geodatabase of Los Angeles city SWITRS data.
If you are interested in collision data geocoding services for other locations in California or nationwide, please contact us at info@roadsafegis.com for a quote.