≡ Roads checking…
Road conditions
Roads Road incidents are events. Road conditions are not.
no key required CORS-open
Place scopes every section below · incidents arrive through
/events?layer=road_incident; conditions are projections of live
state, served only as the road_segment and
chain_control map layers
Incidents severity · headline · id What this is
CHP incidents, AI-enhanced into a readable summary with an impact-driven severity,
and Caltrans lane closures a crew has set up, composed from Caltrans's own fields.
These are stored events — the same records
/events?layer=road_incident returns — so a row opens the
full record and its revision history.
Planned closures severity · headline · planned window What this is
Caltrans roadwork windows that are scheduled but not set up yet, one event per window,
from the same layer with status: SCHEDULED. A multi-day job
is one row per day.
When the crew radios the closure set up, it moves to Incidents. When they pick it up, or
Caltrans cancels it, it resolves.
Road segments GET …/map/road_segment.geojsonroad · status · congestion · travel · delay · distance What this is
One row per monitored road, live from Google Routes travel times and Caltrans status.
Delay is against the road's free-flow duration; status is AI-determined, with the
explanation shown when a road is not fully open.
A segment is baseline state — it never appears in
/events.
Chain control GET …/map/chain_control.geojsonlevel · highway · direction · note What this is
Active chain requirements from Caltrans — R1 chains or 4WD · R2 chains except 4WD ·
R3 chains required, all vehicles.
Empty means none
An empty table means Caltrans reported no controls. A failed feed shows
UNAVAILABLE in the source block above.
To read those two condition layers as geometry — with their
metadata block beside the map — use the
Map screen.