Will it fit?

This is an experimental extension to the cross-section check tool. Given input data:

• the available width along roads
• a route
• a set of cross-sections with different minimum width requirements

Split the route and indicate what cross sections fit where.

Attempt to do all of this purely in the browser, leveraging cloud-native file formats for reading subsets of large input data.

Developer guide

To run everything in this repo, you'll need:

• npm
• wasm-pack
• ogr2ogr
• mapshaper
• Rust

The web app expects web/public/out.fgb to be a flatgeobuffer file with polygons in WGS84 representing space that roads can't go (such as buildings). There are scripts in data_prep/ to build these from different sources; please see there for examples.

To run the web app, cd web; npm i to initially install dependencies. Then npm run wasm (for fast compilation but slow runtime, npm run wasm-release for the opposite tradeoff) whenever the Rust code in backend/ changes. Finally, npm run dev starts the web app locally and automatically picks up changes in web/.

Code overview

• widths is a library that takes a route and polygons to avoid, and generates perpendicular test lines at regular intervals along the route
• backend is the WASM "backend" paired with the web frontend
• cli takes an OSM PBF or XML input and calculates the width along all OSM road segments. The goal here is to compare the physical width and lane tagging, inferring street parking and other interesting questions.

All of the above needs a flatgeobuf file with polygons to treat as constraints on road width. data_prep/ has some approaches designed to work with free INSPIRE data and non-free Ordnance Survey data.

• data_prep/dissolver is a WIP rewrite of the mapshaper polygon dissolve algorithm that can limit the area of output polygons
• data_prep/fix_osmm is a script to convert OS MasterMap mbtiles (one of the only provided formats) into flatgeobuf, for easier use elsewhere.
• data_prep/merge_files is a script to turn many GeoJSON files into one flatgeobuf file, used for the INSPIRE script