District Traffic Data
Download the latest 5-minute aggregate file or browse recent files.
View 5-minute field specifications →| District | Dataset | Downloads |
|---|---|---|
| 03District 3 | 5-minute aggregate | |
| 04District 4 | 5-minute aggregate | |
| 05District 5 | 5-minute aggregate | |
| 06District 6 | 5-minute aggregate | |
| 07District 7 | 5-minute aggregate | |
| 08District 8 | 5-minute aggregate | |
| 10District 10 | 5-minute aggregate | |
| 11District 11 | 5-minute aggregate | |
| 12District 12 | 5-minute aggregate |
These are 5-minute aggregate data, not 30-second raw observations. Data availability and publication times may vary by district.
Data Format & Field Specifications
Use these field definitions to interpret the traffic data and match station identifiers to the station configuration metadata.
5-Minute Aggregate DataStation-level summaries and repeating per-lane fields
Station-Level Fields
| Field | Description | Units / format |
|---|---|---|
| Timestamp | Beginning of the summary interval. For example, 08:00:00 covers measurements collected from 08:00:00 through 08:04:59. Seconds are always 00 for five-minute aggregations. | MM/DD/YYYY HH24:MI:SS |
| Station | Unique station identifier. Use this value to cross-reference the metadata files. | Identifier |
| District | Caltrans district number. | District # |
| Freeway # | Freeway number. | Freeway # |
| Direction of Travel | Direction of travel. | N | S | E | W |
| Lane Type | Lane classification. See the lane type codes below. | Code |
| Station Length | Segment length covered by the station. | miles |
| Samples | Total number of samples received for all lanes. | Count |
| % Observed | Percentage of individual lane points at this location that were observed rather than imputed. | % |
| Total Flow | Sum of flows over the five-minute period across all lanes. The basic five-minute rollup normalizes flow by the number of good samples received from the controller. | Vehicles / 5 min |
| Avg Occupancy | Average occupancy across all lanes over the five-minute period, expressed as a decimal from 0 to 1. | Fraction (0–1) |
| Avg Speed | Flow-weighted average speed across all lanes over the five-minute period. If flow is 0, the arithmetic mean of five-minute station speeds is used. | mph |
Lane Type Codes
- CD
- Collector / distributor
- CH
- Conventional highway
- FF
- Freeway-to-freeway connector
- FR
- Off-ramp
- HV
- HOV
- ML
- Mainline
- OR
- On-ramp
Per-Lane Fields
The following five fields repeat for each lane. N ranges from 1 to the number of lanes at the station.
| Field | Description | Units / format |
|---|---|---|
| Lane N Samples | Number of good samples received for lane N. | Count |
| Lane N Flow | Total flow for lane N over the five-minute period, normalized by the number of good samples. | Vehicles / 5 min |
| Lane N Avg Occ | Average occupancy for lane N, expressed as a decimal from 0 to 1. | Fraction (0–1) |
| Lane N Avg Speed | Flow-weighted average of lane N speeds. If flow is 0, the arithmetic mean of five-minute lane speeds is used. | mph |
| Lane N Observed | Indicates whether the data were observed or imputed. | 1 = observed; 0 = imputed |
Reading occupancy: Occupancy values are described as fractions from 0 to 1: for example, 0.25 means 25%. The source specification labels the units as “%”; this draft follows the stated decimal representation, pending confirmation.
30-Second Raw DataField-reported samples and repeating per-lane measurements
This section describes the 30-second feed format. Download links will be added once available.
Record Fields
| Field | Description | Units / format |
|---|---|---|
| Timestamp | Sample time as reported by the field element. | MM/DD/YYYY HH24:MI:SS |
| Station | Unique station identifier. Use this value to cross-reference the metadata files. | Identifier |
Per-Lane Fields
The following three fields repeat for each lane. N ranges from 1 to the number of lanes at the station.
| Field | Description | Units / format |
|---|---|---|
| Lane N Flow | Number of vehicles that passed over the detector during the sample period. | Vehicles / sample period |
| Lane N Occupancy | Occupancy of lane N during the sample period, expressed as a decimal from 0 to 1. | Fraction (0–1) |
| Lane N Speed | Speed as measured by the detector. Empty if the detector does not report speed. | mph |
Reading occupancy: Values are described as fractions from 0 to 1; 0.25 means 25%. The decimal representation is pending confirmation against the source specification’s “%” unit label.
Which file should I use?
“Latest TXT” links to the district’s 5minagg_latest.txt file. “Recent files” opens its 5-minute data directory, where you can select a timestamped file. Your browser may display a text file instead of downloading it; use your browser’s Save option to keep a local copy.
What is available during the upgrade?
This page provides selected district 5-minute aggregate data links and station configuration metadata. It does not replace the full PeMS interactive application or its historical reporting tools. The new PeMS system is expected in Q2 2027.