Japan train lines Mapbox+Leaflet

trainlines.js

const map = ...;
const accessToken = "...";

// Add train lines (Shinkansen, metro, JR, etc) to Mapbox using LeafLet for a more
// accurate representation of Japan and Tokyo
// Using the layer mapbox.transit-v2 for trains and some custom styles
const trains =
  "https://api.mapbox.com/v4/mapbox.transit-v2/{z}/{x}/{y}.vector.pbf?access_token={accessToken}";
const transit_line = (properties, zoom) => {
  const isShinkansen = properties.mode === "high_speed_rail";
  const isYamanote = properties.name === "山手線";
  return {
    color: (isYamanote ? "#00cc00" : properties.line_color) || "#666",
    opacity: isShinkansen ? 0.75 : 0.5,
    weight: isShinkansen || isYamanote ? 2 : 1.5
  };
};
var mapillaryLayer = L.vectorGrid
  .protobuf(trains, { accessToken, vectorTileLayerStyles: { transit_line } })
  .addTo(map);