Search or browse any of California's 105 sensor-equipped freeways and highways (I-405, SR-91, I-210, I-805, US-101, I-5, and more) to replay 24 hours of real traffic every 5 minutes. Tap any crash, slowdown, 911 log, or road closure to zoom straight to that exact spot on the map.
2026-11-08 · 96 road sensors (Mile 0.4 to 72.1) · Slowdowns ripple backward at 14.2 mph
Tap any crash, 911 dispatch call, lane closure, or live traffic camera below to jump back up to the freeway map, set the replay clock to that moment, and zoom right in on that exact spot.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Matched to the nearest freeway road sensor, though 5-minute speed readings right before the crash were not recorded.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
Traffic was moving at steady freeway speeds with only a small speed difference between neighboring lanes.
When a single vehicle crosses a road sensor alone during a 30-second window, how long it covers the sensor distinguishes everyday passenger cars (~18 ft) from long trucks and buses (35+ ft).
| Local time | Lane | Speed | Vehicle type | Est. length |
|---|---|---|---|---|
| 10:52 PM PT | Lane 1 | 78.0 mph | Passenger car | 17.0 ft |
| 10:52 PM PT | Lane 1 | 71.0 mph | Passenger car | 14.9 ft |
| 10:56 PM PT | Lane 1 | 78.0 mph | Passenger car | 17.0 ft |
| 10:56 PM PT | Lane 1 | 65.0 mph | Passenger car | 16.3 ft |
| 10:59 PM PT | Lane 1 | 71.0 mph | Passenger car | 18.4 ft |
| 10:59 PM PT | Lane 1 | 71.0 mph | Passenger car | 14.9 ft |
| 11:00 PM PT | Lane 1 | 71.0 mph | Passenger car | 18.4 ft |
| 11:02 PM PT | Lane 1 | 86.0 mph | Passenger car | 19.4 ft |
| 11:03 PM PT | Lane 1 | 71.0 mph | Passenger car | 14.9 ft |
| 11:03 PM PT | Lane 3 | 70.0 mph | Passenger car | 18.0 ft |
| 11:05 PM PT | Lane 1 | 65.0 mph | Passenger car | 16.3 ft |
| 11:13 PM PT | Lane 1 | 78.0 mph | Passenger car | 17.0 ft |
| 11:16 PM PT | Lane 1 | 71.0 mph | Passenger car | 18.4 ft |
| 11:16 PM PT | Lane 1 | 78.0 mph | Passenger car | 17.0 ft |
| 11:19 PM PT | Lane 4 | 60.0 mph | Passenger car | 14.6 ft |
| 11:19 PM PT | Lane 1 | 86.0 mph | Passenger car | 19.4 ft |
| 11:20 PM PT | Lane 1 | 71.0 mph | Passenger car | 18.4 ft |
| 11:20 PM PT | Lane 1 | 65.0 mph | Passenger car | 19.4 ft |
When freeway traffic suddenly stops ahead on I-405 South (San Diego Freeway) · Los Angeles & Orange County, the backup ripples backward toward oncoming cars. Drag the two sliders below to see whether turning on an overhead digital sign earlier gives drivers room to slow down smoothly instead of slamming on their brakes.
| Sign location | Mile | Distance | Backup reaches sign | Message shown | Map |
|---|---|---|---|---|---|
| North of Lakewood | 3.8 | 1.7 mi | +7.1 min | VINCENT THOMAS | BRIDGE CLOSED | USE ALT ROUTES | |
| Wilmington Ave | 9.5 | 4.0 mi | +16.9 min | Blank (standby) | |
| West of Rte 405 | 1.4 | 4.1 mi | +17.2 min | VINCENT THOMAS | BRIDGE CLOSED | USE ALT ROUTES | |
| Cms 88 - Irvine Center Drive 0.85 N405 | 0.8 | 4.6 mi | +19.5 min | MINUTES TO: | RTE 55 10 |
Each dot is 1 hour at 1 road sensor. Teal dots are smooth highway speeds; orange and red dots are crowded slowdowns. The dashed gold line shows how fast a backup ripples backward (14.2 mph).
Every few tenths of a mile, Caltrans sensors built into the freeway pavement count passing vehicles and measure speeds in each lane every 30 seconds and 5 minutes, paired with live digital freeway signs, road work logs, and traffic cameras.
Major routes such as I-405 across Orange and Los Angeles counties are connected end to end by milepost so you can follow a traffic slowdown across county lines, with reported CHP crashes matched to the closest road sensor.
Road sensors show how fast traffic was moving, whether a backup was already building, and how sharply neighboring lanes differed in speed around the time of a crash. They do not show what caused a crash or who was at fault.