Isochrone

Isochrone maps are commonly used to depict areas of equal travel time. Build isochrones using OSRM, Turf and concaveman.

Installation

npm install osrm isochrone

Usage

Building OSRM graph

This package consumes preprocessed OSRM graph as an input. To build such a graph you have to extract it from your OSM file with one of profiles and build it using one of the algorithms (Contraction Hierarchies or Multi-Level Dijkstra).

To build OSRM graph using isochrone package, you can clone the source code and install dependencies

git clone https://github.com/stepankuzmin/node-isochrone.git
cd node-isochrone
npm i

Here is an example of how to extract graph using foot profile and build it using contraction hierarchies algorithm.

wget https://s3.amazonaws.com/mapbox/osrm/testing/monaco.osm.pbf
./node_modules/osrm/lib/binding/osrm-extract -p ./node_modules/osrm/profiles/foot.lua monaco.osm.pbf
./node_modules/osrm/lib/binding/osrm-contract monaco.osrm

Example

See API for more info.

const OSRM = require("osrm");
const isochrone = require("isochrone");

const osrm = new OSRM({ path: "./monaco.osrm" });

const startPoint = [7.42063, 43.73104];

const options = {
  osrm,
  radius: 2,
  cellSize: 0.1,
  intervals: [5, 10, 15]
};

isochrone(startPoint, options).then(geojson => {
  console.log(JSON.stringify(geojson, null, 2));
});