Take it on the road: How RCD Helps Field Researchers Report Culvert Condition even when Offline

Abstract

Volunteer field crews documenting culvert condition, roadside ditches, and storm drains routinely work in rural and mountainous terrain where cellular and Wi-Fi access is unreliable or absent, but documenting culvert conditions in remote locations is a situation where accurate, photo-supported reporting matters. Existing platforms such as Survey123 assume continuous connectivity and impose licensing constraints, limited offline customization, and restricted data ownership. These restrictions make them poorly suited to community-driven monitoring efforts. To address this, we built a mobile-compatible Progressive Web App (PWA) for the Culvert Crawlers community science network that captures structured observations, GPS coordinates, and photographic evidence entirely on-device, then synchronizes research data automatically once connectivity is restored. The architecture separates storage by data type: compact survey fields are queued as JSON in localStorage, while photos are persisted as Blobs in IndexedDB and linked to their parent record by unique ID, avoiding binary overflow in Web Storage and preserving images across device restarts. Synchronization is controlled with a confirmed server reachability check; local data is cleared only after the backend acknowledges successful persistence, eliminating data loss from dropped connections midupload. Deployed to real field users, the app has processed over 400 reports with a 100% submission success rate and zero data loss, enabling town managers and volunteer observers alike to document and act upon infrastructure conditions with minimal training and no specialized equipment.