Room to Breathe
Open-source crowd-crush prevention for any gathering: religious, entertainment, sports or political.
People in a crowd crush die because they cannot breathe: the crowd presses on their chests until there is
no room to take a breath. Everything in this project serves one goal: keep room to breathe for every
person, in every crowd.
Room to Breathe helps an administrative body, from a village temple committee to a national disaster authority, to:
- Plan: compute a venue's safe capacity and assess the event's risk before granting a permit.
- See: measure crowd density (people/m²) and motion live, from existing CCTV, phones or gate counters.
- Predict: warn minutes before a zone becomes critical ("Hall reaches critical density in ~10 min").
- Act: turn every alert into pre-approved, explained actions: which gate to close, which to open, and what to announce in Hindi, Bengali or English.
People die in crowd crushes from compressive asphyxia, often while standing still. The causes are
structural: too many people, too few exits, a surge trigger, and decisions that come too late.
All of that is measurable, and therefore preventable.
Works on any phone or computer browser. It asks two things and gives one answer:
- Where is your event? Find it on the map (satellite view, anywhere in the world), trace the area people
will stand in, and tap across each gate. Areas and gate widths are measured for you.
- How many people are coming?
Check my event then says Safe, Possible with precautions or Not safe, with the reasons and what to
change. It runs the checks a crowd-safety expert would: capacity with the largest exit blocked, crowding as
people arrive, a sudden surge (with and without the response plan), and a full evacuation. The engine is the
same one the live control room uses, running inside your browser.
3. The area around the venue then plans the surroundings as well as the venue itself. Using free
OpenStreetMap data, it routes the crowd and its traffic through the real streets, stations and stops, both
arriving and leaving. It finds the outside choke points, which roads to close (each with a diversion), and the
junctions where crowd meets traffic. It names the receiving hospitals with drive times under event traffic,
and plans an ambulance route that avoids the crowd. Then it says where to place police, traffic police,
first aid, ambulances, stewards and station staff, how many, when and why, on one map with a printable plan
for every agency, plus a briefing sheet for each agency. If a street on the map is wrong, tap it to correct its
footpath width or mark it closed or blocked, then re-plan in seconds. On the command line:
rtb overview venue.json --people 60000 --html plan.html --briefings briefings/.
How it works and its limits: docs/SURROUNDINGS.md.
Also in the app: Count a crowd from a photo (people per m², the photo never leaves your device), a
Gate counter for volunteers, and a Permit check. Planners can open Try your own scenario for
surges, blocked gates and evacuations of their choosing. On the command line: rtb assess venue.json --people 12000.
Live monitoring of real cameras runs on a computer at your venue: see Use it at a real event.
Try it in 60 seconds
python3 -m venv .venv && source .venv/bin/activate
pip install "roomtobreathe[server]"
roomtobreathe demo # open http://127.0.0.1:8000
Or run it in Docker: docker run -p 8000:8000 ghcr.io/abhipatelz/roomtobreathe.
The demo simulates an evening rush at a puja pandal. Free prasad starts in the hall, word spreads, and people stop on the exit steps.
Watch the hall go from green to red. Then press Execute all on the RED alert and watch the crowd recover.
No browser? The same scenario runs headless:
roomtobreathe simulate # no action: the hall reaches 7.4 p/m² (crush conditions)
roomtobreathe simulate --respond # playbook executed: every zone stays below 3.7 p/m²
roomtobreathe capacity --area 960 --exit 3 --exit 2.5
What the demo shows (reproducible, see tests/test_core.py)
| Without response | With the Room to Breathe playbook |
|---|
| First warning (ORANGE) | t = 4.6 min | same |
| RED alert | t = 17.0 min | same |
| True density hits critical (6.5 p/m²) | t = 30.0 min, 13 min after the RED alert | never |
| Peak density in any zone | 7.4 p/m² | 3.7 p/m² |
False ORANGE/RED alarms in the steady baseline | 0 | 0 |
An early version of the playbook simply sealed the hall entrance. The simulator showed the crush moving
into the corridor behind it (9 p/m²). The default playbook now follows the crowd-safety rule
hold people back upstream, never seal the gate at the crush point, and a regression test enforces it.
Use it at a real event
Read docs/DEPLOY.md. It walks a district office or organising committee through the
whole event, from the physics that sets the time margin to the after-action record. The short version:
This is the beginning of the README. Read the rest at the original. Read the full README ↗
