Tools · Analysis & Visualizations

SWITRS Query & Map

Walk through the three-step workflow to retrieve crash data from SWITRS, apply filters, and find summary of crashes in map, charts, and tables.

Overview

The SWITRS Query & Map tool accesses crash records from the California Statewide Integrated Traffic Records System (SWITRS). Launch it from the Analysis & Visualizations menu under SWITRS Query & Map. The interface guides you through three steps: picking dates and geography, selecting filters, and reviewing results.

Step 1 – Select date and location

Step 1 interface for selecting dates and locations
Start by defining the analysis timeframe and geography.

Choose a timeframe

Date picker for SWITRS Query & Map
Select start and end dates with calendars or by typing values.

Type dates directly or use the calendar picker. The default range shows the most recent complete year, with provisional data for newer years when available.

Note Broad date ranges across multiple years may take longer to query.

Select geographies

After choosing dates, pick a county. Then decide whether to filter by cities or state highways within that county.

  • City: Displays all incorporated cities plus an Unincorporated option.
  • State Highway: Lists routes in the county and allows filtering by direction.
State highway selection example
Switch to state highway mode to focus on specific routes and directions.

Tip Select multiple cities or routes with Ctrl + click (Windows) or ⌘ + click (macOS).

Click Select Filters to move to the next step.

Step 2 – Apply filters

Filter selection interface with crash, party, and victim tabs
Refine results with crash, party, victim, and infrastructure filters.

The filter tabs let you narrow results by crash characteristics, party attributes, victim demographics, or infrastructure context.

Note SWITRS data is hierarchical: crash filters apply first, then party filters, then victim filters. Learn more in Working with the relational database structure.

Crash filters

Crash filters list with selected values
Check relevant filters; selected values appear at the top of the panel.

Toggle filters such as crash severity, type, primary collision factor, or weather. Manage selections with Check All, Uncheck All, and Remove Filter buttons, or remove individual filters from the Current Selection box.

Party filters

Focus on specific party attributes like movement, vehicle type, or driver actions. Party filters refine crashes already matched by crash filters.

Victim filters

Limit results by victim age, role, injury severity, and more. Multiple victims can be associated with each party.

Infrastructure filters

Use Functional Classification to explore roadway context. Additional infrastructure filters may be added in future releases. See the SWITRS geocoding guide for definitions.

When finished, choose Continue to load the results.

Step 3 – Review results

Results summary with filters and charts
The Summary view provides quick counts and export tools.

Use Change Filters to adjust selections at any time. The results page contains several components:

Summary tables & charts

Results summary tables with counts and percentages
View totals and percentages for the most common crash filters.

Review totals for crashes, parties, and victims. Switch between tabs (highlighted in red) to see charts for each category, such as crash severity distributions.

Pie chart of crash severity
Charts visualize filter breakdowns; export icons save images or data.

Export charts and tables

Export buttons for charts

Use the export icons to print or download tables and charts in multiple formats.

Download data files

Download dialog for crash, party, or victim data

Export Crashes, Parties, or Victims CSV files. Crash downloads include geocoded coordinates (POINT_X and POINT_Y) for mapped records.

Cross-reference fields with the SWITRS codebook.

Query options

Query options menu

Use the header options to start a New Query or Query by CASE IDs. When querying by case IDs, enter values separated by commas or spaces, or upload a CSV containing case IDs (for example, from a previous download).

Dialog for loading case IDs

View results on the map

Map of query results with clusters
Open the map to view geocoded crashes, clusters, and heat maps.

Select Map to visualize geocoded crashes. The top banner shows how many crashes were mapped versus total results. Use List Unmapped Crashes to review records without coordinates.

Note Learn more about unmapped crashes in the FAQ below.

Map features

Map feature controls

Clusters vs. heat map

Cluster symbology on SWITRS map
Clusters show counts by color and size; click to drill into intersections.
Crash marker pop-up with details
Select markers to reveal crash specifics.

Switch between cluster and heat map displays depending on how dense your results are. Click cluster markers to see intersection-level summaries, or click individual crashes for detail pop-ups.

Crash details

Crash details page with Street View
The Crash Details page includes Street View imagery and key attributes.

Open Crash Details in the pop-up to view a single crash, inspect the scene with Google Street View, and review factors such as party movement or right-of-way violations.

Frequently asked questions

How can I make queries load faster?

Limit the query by timeframe, location, and filters to reduce the number of records processed. County-wide, multi-year queries can include hundreds of thousands of crashes and take longer to load.

Why do counts differ between SWITRS Query & Map and SWITRS GIS Map?

SWITRS Query & Map includes all crashes, even when they are not geocoded. SWITRS GIS Map only displays geocoded crashes, so totals are typically lower. Use List Unmapped Crashes in the Query & Map tool to identify missing locations.

Why are there fewer crashes than in our local crash database, i.e., Crossroads?

TIMS excludes property-damage-only crashes, focusing on fatal and injury crashes. Some records may also lack geocodes, resulting in fewer mapped crashes.

How do I find out what SWITRS fields and their values mean?

The format of SWITRS data and descriptions of each of the data fields and their range of values are described in the SWITRS Codebook page.

Can you give more information about the geocoded coordinates in the SWITRS data files?

Approximately 97 percent of fatal and injury crashes have been geocoded through a process developed at SafeTREC. The POINT_X and POINT_Y fields contain the longitude/latitude geocoded coordinate locations based on the 1984 World Geodetic System (WGS84). If the crash was unable to be geocoded, these two fields will remain blank. If you are downloading a subset of data, it will include all crashes that matched your criteria, but if you use the mapping tools only crashes that were geocoded will be displayed. Note that these geocoded coordinate locations are different from the GPS coordinates that are also provided by SWITRS which are available by LATITUDE and LONGITUDE fields.

How do I display downloaded SWITRS datasets in other GIS software or applications?

There are countless software and web applications for displaying data with XY coordinates. Each application will have its own steps, but it should be relatively straightforward. Here is the Add XY data help article for displaying data in ArcGIS.

Why are there fewer crashes in the most recent year of data available?

It currently takes about 12-18 months for the California Highway Patrol (CHP) to finalize SWITRS crash data. For example, the final dataset for 2024 will likely not be available until summer 2026. On TIMS, we extract the most recent year of data available from the CHP on a quarterly basis. It will contain whatever records have already been input by CHP before that date. Therefore, until the most recent year is finalized, it will likely show fewer crashes in TIMS.