NetworkForge
Build routable networks for Valhalla and other routers: add your own roads, cycleways and paths to OpenStreetMap, change or close streets, and get before and after OSM PBF files and QGIS layers back.
NetworkForge joins a layer of proposed roads, cycleways and paths into the OpenStreetMap network and writes a "before" and an "after" network as OSM PBF files for routers such as Valhalla (routing.earth's Network Analyst plugin), R5 (Easy-R5, for public transport) and others, with both networks loaded in QGIS as a preview. Existing streets can be changed or removed, turns can be banned at junctions, and bollards, signals, crossings and ferries can be added; layers of nodes and turn restrictions show the barriers, signals, crossings and banned turns. A network can also be built from your own lines alone, without OpenStreetMap. "Add traffic (time of day)" gives a network slower speeds at busy times for Valhalla.
This plugin is the QGIS front end. The network logic lives in the separate NetworkForge engine (https://github.com/Yibbzz/networkforge, GPL-3.0), which the plugin runs as a separate program.
External dependency, installed automatically: the first time a tool runs, the plugin downloads the engine and what it needs to run - the uv installer, a Python 3.12 of its own and the engine's Python packages (about 600 MB of disk space). This needs an internet connection and takes a few minutes, once. Nothing is added to QGIS's own Python.
Where it goes: the "networkforge" folder inside your QGIS profile folder (Settings > User Profiles > Open Active Profile Folder), with the Python itself in uv's own data folder. Deleting the "networkforge" folder removes the engine; the plugin installs it again when next needed. A log file, engine.log, is kept in the same folder.
Building a network downloads OpenStreetMap data for the chosen area from the Overpass API, unless you give a local OSM file.
Limitations: no public transport of its own (R5 adds it from GTFS timetables) and no traffic simulation; QGIS's own network tools ignore turn restrictions and barriers (the turn restrictions and nodes layers show them; routers obey them). Existing streets can be changed or removed, not redrawn.
Map data © OpenStreetMap contributors (ODbL).