Use Tile Reduce and OSM QA Tiles to find the difference between OSM roads and Tiger roads

difference.js

var turf = require('turf'),
  flatten = require('geojson-flatten'),
  normalize = require('geojson-normalize'),
  tilebelt = require('tilebelt');

module.exports = function(tileLayers, tile, done) {
  // concat feature classes and normalize data
  var tigerRoads = normalize(tileLayers.tiger.tiger20062014);
  var osmData = normalize(tileLayers.osmdata.migeojson);

  // filter out roads that are shorter than 30m and have no name
  tigerRoads.features.forEach(function(road, i) {
    if (filter(road)) tigerRoads.features.splice(i,1);
  });

  // clip features to tile
  osmData = clip(osmData, tile);
  tigerRoads = clip(tigerRoads, tile);
  osmData = normalize(flatten(osmData));
  tigerRoads = normalize(flatten(tigerRoads));

  // buffer streets
  var streetBuffers = turf.featurecollection([]);
  streetBuffers.features = osmData.features.map(function(f){
    if (f.properties.highway) {
      return turf.buffer(road, 20, 'meters').features[0];
    }
  });
  streetBuffers = normalize(turf.merge(streetBuffers));

  // erase street buffer from tiger lines
  var tigerDeltas = turf.featurecollection([]);

  if (tigerRoads && streetBuffers) {
    tigerRoads.features.forEach(function(tigerRoad){
      streetBuffers.features.forEach(function(streetsRoad){
        var roadDiff = turf.erase(tigerRoad, streetsRoad);
        if(roadDiff && !filter(roadDiff)) tigerDeltas.features.push(roadDiff);
      });
    });
  }

  done(null, tigerDeltas);
};

function clip(lines, tile) {
  lines.features = lines.features.map(function(line){
    try {
      var clipped = turf.intersect(line, turf.polygon(tilebelt.tileToGeoJSON(tile).coordinates));
      return clipped;
    } catch(e){
      return;
    }
  });
  lines.features = lines.features.filter(function(line){
    if(line) return true;
  });
  lines.features = lines.features.filter(function(line){
    if(line.geometry.type === 'LineString' || line.geometry.type === 'MultiLineString') return true;
  });
  return lines;
}

function filter(road) {
  var length = turf.lineDistance(road, 'kilometers');
  if (length < 0.03 || road.properties.fullname == '') {
    return true;
  } else {
    return false;
  }
}

index.js

var TileReduce = require('tile-reduce');
var turf = require('turf');
var bbox = [4293,6022,14];

//var area = JSON.parse(argv.area);
var opts = {
  zoom: 15,
  tileLayers: [
    {
      name: 'osmdata',
      url: __dirname + '/latest.planet.mbtiles',
      layers: ['osm']
    },
    {
      name: 'tiger',
      url: __dirname + '/tiger.mbtiles',
      layers: ['tiger']
    }
  ],
  map: __dirname + '/difference.js'
};

var tilereduce = TileReduce(bbox, opts);
var diff = turf.featurecollection([]);

tilereduce.on('reduce', function(result){
  diff.features = diff.features.concat(result.features);
});

tilereduce.on('end', function(error){
  console.log(JSON.stringify(diff));
});

tilereduce.on('error', function(err){
  throw err;
});

tilereduce.run();

Shouldn't you do a reverse for loop instead of the forEach loop on this splicing ?

// filter out roads that are shorter than 30m and have no name
for (var i = tigerRoads.features.length - 1; i >= 0; i -= 1) {
    if (filter(road)) tigerRoads.features.splice(i,1);
}