A wireframe stylesheet written in carto for OSM data

osm-wireframe-bw.mml

{
  "bounds": [
    -180,
    -85.05112877980659,
    180,
    85.05112877980659
  ],
  "center": [
    0,
    0,
    8
  ],
  "format": "png",
  "interactivity": false,
  "minzoom": 0,
  "maxzoom": 22,
  "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
  "Stylesheet": [
    "wireframe.mss"
  ],
  "Layer": [
    {
      "geometry": "linestring",
      "name": "way",
      "id": "way",
      "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
      "class": "",
      "Datasource": {
        "table": "(SELECT way FROM planet_osm_line) AS ways",
        "key_field": "",
        "geometry_field": "way",
        "extent": "",
        "type": "postgis",
        "host": "localhost",
        "port": "5432",
        "user": "",
        "password": "",
        "dbname": ""
      }
    }
  ],
  "name": "osm-wireframe-bw",
  "description": "A black and white wireframe of ways in OSM"
}

wireframe.mss

/*
 * Wireframe stylesheet for OSM data.
 *
 * Author: Andrew Harvey <andrew.harvey4@gmail.com>
 * License: CC0 http://creativecommons.org/publicdomain/zero/1.0/
 * To the extent possible under law, the person who associated CC0
 * with this work has waived all copyright and related or neighboring
 * rights to this work.
 */

#way{
  line-color: #000000;
  line-opacity: 0.5;
  line-join: round;
  line-cap: round;
  
  [zoom>11] { line-width: 1; }
  [zoom=11] { line-width: 0.8; }
  [zoom=10] { line-width: 0.6; }
  [zoom=9] { line-width: 0.4; }
  [zoom<9] { line-width: 0.2; }
}