$ npm install -g gtfsmerge$ gtfsmerge input1.zip input2.zip output.zipEvery argument but the last is a feed to merge; the last is where the merged feed goes, as a .zip
or a directory.
What merging does
- Transfers are created between stops close enough to walk between.
- Duplicate stops, agencies and routes are assumed to be the same and written once.
- Calendars, calendar dates, routes, trips and stop times are re-indexed.
- Identical calendars are merged into a single entry.
- Calendars and calendar dates in the past are removed, along with their trips.
- A calendar date with no calendar has one synthesised for it.
- Unused stops are removed, and a transfer to one goes with it.
- A call at a platform becomes a call at the station above it.
- A
transfer_type4 coupling is carried through, pointing at the renumbered trips. - Routes can be removed by type.
Fares files are not processed. Raise an issue if you would like that.
Options
The distance in kilometres within which transfers are generated for nearby stops:
gtfsmerge --transfer-distance 2 input1.zip input2.zip output.zipRoutes can be removed based on their type:
gtfsmerge --remove-route-types 0,1,4 input1.zip input2.zip output.zipAnything that finished before today is dropped. --no-date-filter keeps it all; --date-filter
pins the cutoff, which is what you want for a reproducible merge:
gtfsmerge --date-filter 20260601 input1.zip input2.zip output.zipGenerated transfer distances use a flat-earth approximation calibrated at one latitude, 54 by default, which is the middle of Great Britain. Elsewhere:
gtfsmerge --ruler-latitude 40 input1.zip input2.zip output.zipgtfsmerge --help lists everything.
Stop identity
Stops with the same id in different feeds are assumed to be the same stop, which is usually what you
want: a GB rail feed from cif2gtfs and a GB bus feed from
transxchange2gtfs both name a stop by its ATCO code, so they
merge without any reconciliation.
Where two feeds genuinely disagree, prefix one of them first:
gtfsmerge --stop-prefix input1_ input1.zip modified-input1.zip
gtfsmerge modified-input1.zip input2.zip output.zipMemory
A whole feed is held in memory while it is merged, so bin/gtfsmerge.sh runs node with
--max-old-space-size=8000. stop_times.txt is the only file that has to be buffered, and only
because the stop times cannot be renumbered until the trips have been — a two-pass read would
remove the largest allocation in the tool.
Requirements
Node.js 22 or later. No zip binary is needed — the archive is written in process.
gtfsmerge on npm · source · GPL v3