diff --git a/agenda/trip.py b/agenda/trip.py
index db148e9..2a4f7ee 100644
--- a/agenda/trip.py
+++ b/agenda/trip.py
@@ -165,9 +165,8 @@ def latlon_tuple(stop: StrDict) -> tuple[float, float]:
     return (stop["latitude"], stop["longitude"])
 
 
-def read_geojson(filename: str) -> str:
+def read_geojson(data_dir: str, filename: str) -> str:
     """Read GeoJSON from file."""
-    data_dir = flask.current_app.config["PERSONAL_DATA"]
     return open(os.path.join(data_dir, "train_routes", filename + ".geojson")).read()
 
 
@@ -238,8 +237,10 @@ def get_trip_routes(trip: Trip) -> list[StrDict]:
 
 
 def get_coordinates_and_routes(
-    trip_list: list[Trip],
+    trip_list: list[Trip], data_dir: str | None = None
 ) -> tuple[list[StrDict], list[StrDict]]:
+    if data_dir is None:
+        data_dir = flask.current_app.config["PERSONAL_DATA"]
     coordinates = []
     seen_coordinates: set[tuple[str, str]] = set()
     routes = []
@@ -260,6 +261,6 @@ def get_coordinates_and_routes(
 
     for route in routes:
         if "geojson_filename" in route:
-            route["geojson"] = read_geojson(route.pop("geojson_filename"))
+            route["geojson"] = read_geojson(data_dir, route.pop("geojson_filename"))
 
     return (coordinates, routes)
diff --git a/validate_yaml.py b/validate_yaml.py
index e506441..75fb42e 100755
--- a/validate_yaml.py
+++ b/validate_yaml.py
@@ -14,6 +14,10 @@ data_dir = config.PERSONAL_DATA
 trip_list = agenda.trip.build_trip_list(data_dir)
 print(len(trip_list), "trips")
 
+coords, routes = agenda.trip.get_coordinates_and_routes(trip_list, data_dir)
+print(len(coords), "coords")
+print(len(routes), "routes")
+
 flights = agenda.travel.parse_yaml("flights", data_dir)
 print(len(flights), "flights")