Add car journeys to trips

docs/personal-data-yaml.md

@@ -23,6 +23,7 @@ This document describes the YAML files read from `../personal-data/`. It is inte
 - `ferries.yaml` `from` and `to` values reference `ferry_terminals.yaml` `name`.
 - `buses.yaml` `from` and `to` values reference `bus_stops.yaml` `name`.
 - `coaches.yaml` `from` and `to` values reference `coach_stations.yaml` `name`.
+- `car_journeys.yaml` `route` values name files in `car_routes/`. The `.geojson` extension is optional.
 - Station, stop, and terminal `routes` values name GeoJSON files without the `.geojson` extension.
 
 ## `accommodation.yaml`
@@ -250,6 +251,41 @@ Example:
     base_fare: '55.00'
 ```
 
+## `car_journeys.yaml`
+
+Top-level shape: list of car journeys.
+
+Used by: trip loading, maps, trip timeline. Car journeys are for driving your own car or a rental car.
+
+Required fields:
+
+- `trip`: trip start date.
+- `depart`: departure date or datetime.
+- `arrive`: arrival date or datetime.
+- `route`: GeoJSON filename in `car_routes/`, with or without the `.geojson` extension.
+
+Optional fields:
+
+- `from`, `to`: endpoint labels. If omitted and the route filename uses `A_to_B`, labels are inferred from the filename.
+- `from_type`, `to_type`: marker type override. Use `home` to render a house icon. Otherwise car endpoints render as car markers.
+- `operator`, `vehicle`, `price`, `currency`, `distance`.
+
+The route distance is calculated from the GeoJSON when `distance` is not present. If an inferred or explicit endpoint label is `home`, `PCH`, or `Picture House Court`, the marker is rendered as a house.
+
+Example:
+
+```yaml
+- trip: 2026-07-16
+  depart: 2026-07-16
+  arrive: 2026-07-16
+  route: PCH_to_EMF.geojson
+
+- trip: 2026-07-16
+  depart: 2026-07-19
+  arrive: 2026-07-19
+  route: EMF_to_PCH.geojson
+```
+
 ## `conferences.yaml`
 
 Top-level shape: list of conferences and conference-like events.