Related : I'm building https://github.com/laem/cartes , an alternative to Google Maps. On top of a custom protomaps tileset and a few other MapTiler options (such as satellite and hiking), it packs a search engine, a basic OSM place UI, transit calculators (walk, bike with profiles, transit, car), small features like ruler and favorites, transit maps, photos of places, place search by categories, and the French open…
Are you using opentripplanner for routing?