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Talk Beginner MIT License (Software), Government Open Data License - India (GODL) (Data) First Talk

From Shapefiles to Live Feeds: What It Actually Takes to Open Chennai's Transit Data

Proposal status is Withdrawn
Session Description

  • The Context: Chennai's public transit data exists, but it isn't truly open. GTFS feeds are stale, shapefiles contain duplicate coordinates, and files from different departments do not align spatially. We as Build for bharat fellow built TransitData Hub Chennai for CUMTA (Chennai Unified Metropolitan Transport Authority) to turn this raw data into an open, accessible citizen portal.

  • The Data Struggle: Reconciling route IDs and stops across fragmented agency feeds (MTC buses, CMRL metro, and Suburban Rail) proved highly complex. We will show the actual quality issues logged and how we automated checks to validate and clean the data.

  • Lightweight FOSS Stack: To make the portal self-hostable for any Indian city for under $5/month, we scaled down our architecture from a heavy Kubernetes/Airflow blueprint to a lean stack: Vite, Express, PostGIS, Redis, and Docker.

  • Geospatial & Routing Engine: We model stop coordinates and transit shapes in PostgreSQL/PostGIS. We'll show how we use ST_SimplifyPreserveTopology to optimize route geometries for mobile clients, and how our BFS traversal engine handles multi-modal routing with transfers.

  • Web Crypto Decoupling: To keep server CPU load near zero under high traffic, the API encrypts GeoJSON layers with AES-256-GCM, offloading decryption to the browser using the native Web Crypto API.

  • The GovTech Experience: We cover what "open data" means inside a government body, how data-sharing decisions get made, and what a GovTech intern can practically push through in a single cycle.

Key Takeaways

  • Civic Transit Pipeline: A reproducible pattern for parsing, cleaning, and validating inconsistent GTFS feeds and shapefiles.

  • Pragmatic Stack Design: Why stripping down to a lightweight, single-VM FOSS stack (Vite + Express + Docker) makes civic tech platforms sustainable for community self-hosting.

  • Geospatial Optimization: Practical methods to clean database stop coordinates and simplify geometries for mobile browsers in PostGIS.

  • Client Decryption: Using browser-native Web Crypto APIs to decrypt heavy AES-GCM payloads, protecting data and saving server CPU resources.

  • The GovTech Playbook: Honest insights into navigating data governance, policies, and pushing open-source initiatives inside Indian government bodies.

References

https://opendata.cumta.org/

Session Categories

Knowledge Commons (Open Hardware, Open Science, Open Data etc.)
Talk License: MIT License (Software), Government Open Data License - India (GODL) (Data)

Which track are you applying for?

Main track

Speakers

Bharat Oraon
Bharat Oraon GIS Fellow | Bharat Digital

An Urban Planner graduated from School of Planning and Architecture, Vijayawada, with a focus on urban governance, spatial intelligence, and civic technology for Indian cities.

My work sits at the intersection of urban planning research and geospatial technology — combining GIS analysis, remote sensing, and spatial data infrastructure with policy research on governance reform, mobility systems, and land use planning.

I am interested in how spatial data and civic technology can strengthen planning systems and urban governance in Indian cities — making planning more evidence-based, participatory, and responsive to the needs of all urban residents.

https://www.bharatoraon.com/
Atharva Nile
Atharva Nile Full Stack Fellow

Final-year CSE student at IIIT Nagpur, currently embedded with the CUMTA. I've built a civic tech platform that scaled to real users and a real-time transit ridership dashboard before this. Most of my work lives in the gap between "the data exists" and "the data is usable" — and I've learned that gap is usually a GeoJSON file and three unanswered emails wide.

Vignesh Tamilvanan
Vignesh Tamilvanan Ex Spatial Data Architect - CUMTA | CUMTA

Data scientist, Urban Planner and GIS Specialist with keen interest to apply technology such Spatial Computing, Data Science and AI towards the Sustainable Development of the Global Community