perfect-postcode/pipeline/download/transit_network.py
2026-02-15 22:39:53 +00:00

354 lines
13 KiB
Python

"""Download and prepare transit network data for R5 routing.
Downloads:
- England OSM PBF from Geofabrik (~1.5GB)
- BODS GTFS from Bus Open Data Service (~1.5GB, all England bus/tram/ferry)
Then processes for R5 compatibility:
- Cleans GTFS (fixes stop_times >72h, feed_info year >2100)
- Crops OSM PBF to London bounding box via osmium
- Crops GTFS to London bounding box (keeps only London-touching trips)
Requires: osmium-tool (apt install osmium-tool)
Output directory: property-data/transit/
Final files: london.osm.pbf + bods_gtfs.zip (London-only, R5-ready)
"""
import argparse
import csv
import io
import os
import subprocess
import urllib.request
import zipfile
from pathlib import Path
from tqdm import tqdm
ENGLAND_PBF_URL = (
"https://download.geofabrik.de/europe/united-kingdom/england-latest.osm.pbf"
)
# Bus Open Data Service — pre-converted GTFS covering all England bus/tram/ferry
BODS_GTFS_URL = "https://data.bus-data.dft.gov.uk/timetable/download/gtfs-file/all/"
USER_AGENT = "property-map-pipeline/1.0 (https://github.com)"
# London + Home Counties bounding box (~50km buffer around Greater London)
LONDON_BBOX = {"min_lat": 51.2, "max_lat": 51.85, "min_lon": -0.65, "max_lon": 0.35}
def _download_http(url: str, dest: Path, *, desc: str) -> None:
"""Stream-download a URL to a file with progress bar."""
dest.parent.mkdir(parents=True, exist_ok=True)
tmp = dest.with_suffix(dest.suffix + ".tmp")
req = urllib.request.Request(url, headers={"User-Agent": USER_AGENT})
with (
tqdm(unit="B", unit_scale=True, desc=desc) as bar,
urllib.request.urlopen(req) as resp,
open(tmp, "wb") as f,
):
length = resp.headers.get("Content-Length")
if length:
bar.total = int(length)
while chunk := resp.read(1 << 20):
f.write(chunk)
bar.update(len(chunk))
tmp.rename(dest)
print(f" Saved to {dest}")
def download_osm_pbf(output_dir: Path) -> Path:
"""Download England OSM PBF extract from Geofabrik."""
dest = output_dir / "england.osm.pbf"
if dest.exists():
print(f"OSM PBF already exists: {dest}")
return dest
print("Downloading England OSM PBF (~1.5 GB)...")
_download_http(ENGLAND_PBF_URL, dest, desc="england.osm.pbf")
return dest
def download_bods_gtfs(output_dir: Path) -> Path:
"""Download BODS GTFS (all England bus/tram/ferry timetables)."""
dest = output_dir / "bods_gtfs_raw.zip"
if dest.exists():
print(f"BODS GTFS already exists: {dest}")
return dest
print("Downloading BODS GTFS (~1.5 GB)...")
_download_http(BODS_GTFS_URL, dest, desc="bods_gtfs_raw.zip")
return dest
def clean_gtfs(src: Path, dst: Path) -> None:
"""Fix R5-incompatible entries in GTFS.
- Removes stop_times with arrival/departure hour > 72
- Caps feed_info end_date year to 2099
"""
if dst.exists():
print(f"Cleaned GTFS already exists: {dst}")
return
print("Cleaning GTFS for R5 compatibility...")
with zipfile.ZipFile(src, "r") as zin, zipfile.ZipFile(
dst, "w", zipfile.ZIP_DEFLATED
) as zout:
for info in zin.infolist():
if info.filename == "stop_times.txt":
dropped = 0
with zin.open(info) as f:
header = f.readline()
header_str = header.decode("utf-8").strip()
cols = header_str.split(",")
arr_idx = cols.index("arrival_time") if "arrival_time" in cols else -1
dep_idx = (
cols.index("departure_time") if "departure_time" in cols else -1
)
import tempfile
tmp = tempfile.NamedTemporaryFile(
mode="wb", delete=False, suffix=".txt"
)
tmp.write(header)
for line in f:
line_str = line.decode("utf-8", errors="replace").strip()
if not line_str:
continue
parts = line_str.split(",")
skip = False
for idx in [arr_idx, dep_idx]:
if 0 <= idx < len(parts):
time_val = parts[idx].strip('"')
if ":" in time_val:
try:
hour = int(time_val.split(":")[0])
if hour > 72:
skip = True
break
except ValueError:
pass
if skip:
dropped += 1
else:
tmp.write(line)
tmp.close()
print(f" stop_times: dropped {dropped} rows with hours > 72")
zout.write(tmp.name, "stop_times.txt")
os.unlink(tmp.name)
elif info.filename == "feed_info.txt":
data = zin.read(info).decode("utf-8")
lines = data.strip().split("\n")
header_line = lines[0]
feed_cols = header_line.split(",")
fixed_lines = [header_line]
for line in lines[1:]:
parts = line.split(",")
for i, col_name in enumerate(feed_cols):
if "end_date" in col_name.lower() and i < len(parts):
date_val = parts[i].strip('"')
if len(date_val) == 8:
year = int(date_val[:4])
if year > 2100:
parts[i] = "20991231"
print(f" feed_info: capped end_date {date_val} → 20991231")
fixed_lines.append(",".join(parts))
zout.writestr("feed_info.txt", "\n".join(fixed_lines) + "\n")
else:
zout.writestr(info, zin.read(info))
print(f" Saved to {dst}")
def crop_osm_to_london(src: Path, dst: Path) -> None:
"""Extract London bounding box from England OSM PBF using osmium."""
if dst.exists():
print(f"London OSM PBF already exists: {dst}")
return
bbox = LONDON_BBOX
bbox_str = f"{bbox['min_lon']},{bbox['min_lat']},{bbox['max_lon']},{bbox['max_lat']}"
print(f"Cropping OSM PBF to London bbox ({bbox_str})...")
subprocess.run(
["osmium", "extract", f"--bbox={bbox_str}", str(src), "-o", str(dst), "--overwrite"],
check=True,
)
size_mb = dst.stat().st_size / (1024 * 1024)
print(f" Saved to {dst} ({size_mb:.0f} MB)")
def crop_gtfs_to_london(src: Path, dst: Path) -> None:
"""Crop GTFS to trips touching the London bounding box."""
if dst.exists():
print(f"London GTFS already exists: {dst}")
return
bbox = LONDON_BBOX
print("Cropping GTFS to London area...")
with zipfile.ZipFile(src, "r") as zin:
# Step 1: Find stops in bbox
print(" Finding stops in bbox...")
with zin.open("stops.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
stops_in_bbox = set()
all_stops = list(reader)
for row in all_stops:
lat = float(row["stop_lat"])
lon = float(row["stop_lon"])
if bbox["min_lat"] <= lat <= bbox["max_lat"] and bbox["min_lon"] <= lon <= bbox["max_lon"]:
stops_in_bbox.add(row["stop_id"])
print(f" {len(stops_in_bbox):,} / {len(all_stops):,} stops in bbox")
# Step 2: Find trips touching these stops
print(" Finding trips touching London stops...")
with zin.open("stop_times.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
st_fieldnames = reader.fieldnames
trips_in_bbox = set()
for row in reader:
if row["stop_id"] in stops_in_bbox:
trips_in_bbox.add(row["trip_id"])
print(f" {len(trips_in_bbox):,} trips touch London")
# Step 3: Collect all stop_times for those trips
print(" Collecting stop_times for London trips...")
stop_times_kept = []
with zin.open("stop_times.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
for row in reader:
if row["trip_id"] in trips_in_bbox:
stop_times_kept.append(row)
stops_needed = {row["stop_id"] for row in stop_times_kept}
print(f" {len(stop_times_kept):,} stop_times kept")
# Step 4: Read trips and find needed routes/services/shapes
print(" Reading trips...")
with zin.open("trips.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
trips_fieldnames = reader.fieldnames
all_trips = list(reader)
trips_kept = [t for t in all_trips if t["trip_id"] in trips_in_bbox]
routes_needed = {t["route_id"] for t in trips_kept}
services_needed = {t["service_id"] for t in trips_kept}
shapes_needed = {t.get("shape_id", "") for t in trips_kept} - {""}
# Step 5: Write cropped GTFS
print(" Writing cropped GTFS...")
with zipfile.ZipFile(dst, "w", zipfile.ZIP_DEFLATED) as zout:
# stops
stops_kept = [s for s in all_stops if s["stop_id"] in stops_needed]
_write_csv(zout, "stops.txt", list(all_stops[0].keys()), stops_kept)
# stop_times
_write_csv(zout, "stop_times.txt", st_fieldnames, stop_times_kept)
# trips
_write_csv(zout, "trips.txt", trips_fieldnames, trips_kept)
# routes
with zin.open("routes.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
routes_fn = reader.fieldnames
routes_kept = [r for r in reader if r["route_id"] in routes_needed]
_write_csv(zout, "routes.txt", routes_fn, routes_kept)
# agency (copy all)
zout.writestr("agency.txt", zin.read("agency.txt"))
# calendar
with zin.open("calendar.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
cal_fn = reader.fieldnames
cal_kept = [r for r in reader if r["service_id"] in services_needed]
_write_csv(zout, "calendar.txt", cal_fn, cal_kept)
# calendar_dates
with zin.open("calendar_dates.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
cd_fn = reader.fieldnames
cd_kept = [r for r in reader if r["service_id"] in services_needed]
_write_csv(zout, "calendar_dates.txt", cd_fn, cd_kept)
# shapes (stream — can be very large)
print(" Streaming shapes.txt...")
with zin.open("shapes.txt") as f:
reader = csv.DictReader(io.TextIOWrapper(f))
shapes_fn = reader.fieldnames
shapes_rows = [r for r in reader if r["shape_id"] in shapes_needed]
_write_csv(zout, "shapes.txt", shapes_fn, shapes_rows)
# feed_info + frequencies (copy)
zout.writestr("feed_info.txt", zin.read("feed_info.txt"))
zout.writestr("frequencies.txt", zin.read("frequencies.txt"))
size_mb = dst.stat().st_size / (1024 * 1024)
print(f" Saved to {dst} ({size_mb:.0f} MB)")
def _write_csv(
zout: zipfile.ZipFile, name: str, fieldnames: list[str], rows: list[dict]
) -> None:
buf = io.StringIO()
w = csv.DictWriter(buf, fieldnames=fieldnames)
w.writeheader()
w.writerows(rows)
zout.writestr(name, buf.getvalue())
print(f" {name}: {len(rows):,} rows")
def main() -> None:
parser = argparse.ArgumentParser(
description="Download and prepare transit network data for R5 routing engine"
)
parser.add_argument(
"--output",
type=Path,
required=True,
help="Output directory for transit data",
)
args = parser.parse_args()
output_dir: Path = args.output
raw_dir = output_dir / "raw"
raw_dir.mkdir(parents=True, exist_ok=True)
# Download raw data
england_pbf = download_osm_pbf(raw_dir)
bods_raw = download_bods_gtfs(raw_dir)
# Clean GTFS (fix R5 incompatibilities)
bods_clean = raw_dir / "bods_gtfs_clean.zip"
clean_gtfs(bods_raw, bods_clean)
# Crop to London area for R5 (full England requires >30GB RAM)
london_pbf = output_dir / "london.osm.pbf"
crop_osm_to_london(england_pbf, london_pbf)
london_gtfs = output_dir / "bods_gtfs.zip"
crop_gtfs_to_london(bods_clean, london_gtfs)
# Summary
print()
print("Transit data ready for R5:")
for f in sorted(output_dir.iterdir()):
if f.is_dir() or f.name.startswith("."):
continue
size_mb = f.stat().st_size / (1024 * 1024)
print(f" {f.name}: {size_mb:.1f} MB")
if __name__ == "__main__":
main()