Roads API 會收集路線沿途的最多 100 個 GPS 點,並傳回類似的資料集,其中點會對齊車輛行經的可能道路。您可以選擇要求對點進行內插,產生沿著道路幾何圖形平滑移動的路徑。
要求
必須透過 HTTPS 傳送對齊道路的要求,且格式如下:
https://roads.googleapis.com/v1/snapToRoads?parameters&key=YOUR_API_KEY
Required parameters
path
The path to be snapped. The path parameter accepts a list of latitude/longitude pairs. Latitude and longitude values should be separated by commas. Coordinates should be separated by the pipe character: "|". For example:
path=60.170880,24.942795|60.170879,24.942796|60.170877,24.942796
.Note: The snapping algorithm works best for points that are not too far apart. If you observe odd snapping behavior, try creating paths that have points closer together. To ensure the best snap-to-road quality, you should aim to provide paths on which consecutive pairs of points are within 300m of each other. This will also help in handling any isolated, long jumps between consecutive points caused by GPS signal loss, or noise.
Optional parameters
interpolate
Whether to interpolate a path to include all points forming the full road-geometry. When true, additional interpolated points will also be returned, resulting in a path that smoothly follows the geometry of the road, even around corners and through tunnels. Interpolated paths will most likely contain more points than the original path. Defaults to
false
.
範例
以下要求會將指定的點對齊道路幾何圖形。這組特定資料會沿著環狀道路行駛;設定 interpolate=true
可確保傳回的幾何圖形會與道路的曲率相符。使用 interpolate=false
時,路徑會繼續沿著道路移動,但產生的折線會比較不平滑。
網址
https://roads.googleapis.com/v1/snapToRoads ?interpolate=true &path=-35.27801%2C149.12958%7C-35.28032%2C149.12907%7C-35.28099%2C149.12929%7C-35.28144%2C149.12984%7C-35.28194%2C149.13003%7C-35.28282%2C149.12956%7C-35.28302%2C149.12881%7C-35.28473%2C149.12836 &key=YOUR_API_KEY
cURL
curl -L -X GET 'https://roads.googleapis.com/v1/snapToRoads?path=-35.27801%2C149.12958%7C-35.28032%2C149.12907%7C-35.28099%2C149.12929%7C-35.28144%2C149.12984%7C-35.28194%2C149.13003%7C-35.28282%2C149.12956%7C-35.28302%2C149.12881%7C-35.28473%2C149.12836&interpolate=true&key=YOUR_API_KEY'
回應
對於每個有效的要求,Roads API 會以要求網址中指定的格式傳回回應,例如下方的 JSON 回應。
{ "snappedPoints": [ { "location": { "latitude": -35.27800489993019, "longitude": 149.129531998742 }, "originalIndex": 0, "placeId": "ChIJr_xl0GdNFmsRsUtUbW7qABM", }, { "location": { "latitude": -35.2784195, "longitude": 149.12946589999999 }, "placeId": "ChIJr_xl0GdNFmsRsUtUbW7qABM", }, { "location": { "latitude": -35.2784195, "longitude": 149.12946589999999 }, "placeId": "ChIJ6aXGemhNFmsRZE_zHqhmrG4", }, { "location": { "latitude": -35.2792731, "longitude": 149.12933809999998 }, "placeId": "ChIJ6aXGemhNFmsRZE_zHqhmrG4", }, { "location": { "latitude": -35.2792731, "longitude": 149.12933809999998 }, "placeId": "ChIJTcTdZ2hNFmsRXokM4mWCWfk", }, { "location": { "latitude": -35.279557, "longitude": 149.1292973 }, "placeId": "ChIJTcTdZ2hNFmsRXokM4mWCWfk", }, { "location": { "latitude": -35.279557, "longitude": 149.1292973 }, "placeId": "ChIJiUfNQmhNFmsRSsAI-1m6y1g", }, { "location": { "latitude": -35.279610999999996, "longitude": 149.1292889 }, "placeId": "ChIJiUfNQmhNFmsRSsAI-1m6y1g", }, { "location": { "latitude": -35.2796484, "longitude": 149.1292791 }, "placeId": "ChIJiUfNQmhNFmsRSsAI-1m6y1g", }, { "location": { "latitude": -35.2796484, "longitude": 149.1292791 }, "placeId": "ChIJ_RyFQ2hNFmsRoHJAbW7qABM", }, { "location": { "latitude": -35.279947299999996, "longitude": 149.1291894 }, "placeId": "ChIJ_RyFQ2hNFmsRoHJAbW7qABM", }, { "location": { "latitude": -35.279947299999996, "longitude": 149.1291894 }, "placeId": "ChIJOyypT2hNFmsRZBtscGL0htw", }, { "location": { "latitude": -35.280323564795005, "longitude": 149.1290903128365 }, "originalIndex": 1, "placeId": "ChIJOyypT2hNFmsRZBtscGL0htw", }, { "location": { "latitude": -35.2803426, "longitude": 149.12908529999999 }, "placeId": "ChIJOyypT2hNFmsRZBtscGL0htw", }, { "location": { "latitude": -35.2803426, "longitude": 149.12908529999999 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.280409899999995, "longitude": 149.1290699 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.28048179999999, "longitude": 149.129062 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.2805541, "longitude": 149.1290623 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.280626, "longitude": 149.1290712 }, "placeId": "ChIJr8xRTGhNFmsRzMb-rxgjspc", }, { "location": { "latitude": -35.280626, "longitude": 149.1290712 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.280695099999996, "longitude": 149.12908489999998 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2807629, "longitude": 149.1291046 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2808294, "longitude": 149.1291306 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2809064, "longitude": 149.1291693 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.280968200000004, "longitude": 149.129208 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.28101395754623, "longitude": 149.1292430025548 }, "originalIndex": 2, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.28103840000001, "longitude": 149.1292617 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2810936, "longitude": 149.1293121 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2810979, "longitude": 149.1293176 }, "placeId": "ChIJv5r0smlNFmsR5nunau79Fv4", }, { "location": { "latitude": -35.2810979, "longitude": 149.1293176 }, "placeId": "ChIJpYMSrmlNFmsRXkCoIkZxgBg", }, { "location": { "latitude": -35.281152399999996, "longitude": 149.1294256 }, "placeId": "ChIJpYMSrmlNFmsRXkCoIkZxgBg", }, { "location": { "latitude": -35.281152399999996, "longitude": 149.1294256 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2811784, "longitude": 149.1294706 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2812258, "longitude": 149.1295413 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2812771, "longitude": 149.12960759999999 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281332, "longitude": 149.1296695 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2813904, "longitude": 149.12972670000002 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281451700000005, "longitude": 149.1297788 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28146506991143, "longitude": 149.12978858234607 }, "originalIndex": 3, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28151580000001, "longitude": 149.1298257 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28158259999999, "longitude": 149.129867 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281666099999995, "longitude": 149.1299091 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2817377, "longitude": 149.1299379 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281810899999996, "longitude": 149.1299602 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281884999999996, "longitude": 149.1299765 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.28194399606459, "longitude": 149.1299842294294 }, "originalIndex": 4, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.281959799999996, "longitude": 149.12998629999998 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.282035199999996, "longitude": 149.1299895 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2821254, "longitude": 149.1299851 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.282199999999996, "longitude": 149.1299743 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2822739, "longitude": 149.1299573 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2823468, "longitude": 149.129934 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2824178, "longitude": 149.1299043 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2824379, "longitude": 149.1298945 }, "placeId": "ChIJ601MoWlNFmsR5mvkfPp2ovA", }, { "location": { "latitude": -35.2824379, "longitude": 149.1298945 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.282472999999996, "longitude": 149.1298835 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.2825375, "longitude": 149.1298525 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.28257309999999, "longitude": 149.1298319 }, "placeId": "ChIJe9LPnWlNFmsR7mJw8mYHwG0", }, { "location": { "latitude": -35.28257309999999, "longitude": 149.1298319 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282665400000006, "longitude": 149.12974459999998 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.28274030000001, "longitude": 149.1296645 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282809799999995, "longitude": 149.12957799999998 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.28282136229385, "longitude": 149.12956142620385 }, "originalIndex": 5, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.2828744, "longitude": 149.1294854 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282922299999996, "longitude": 149.1294044 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.282931500000004, "longitude": 149.1293876 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.2830263, "longitude": 149.1291788 }, "placeId": "ChIJaUpThGlNFmsRMHWxoH7EOsc", }, { "location": { "latitude": -35.2830263, "longitude": 149.1291788 }, "placeId": "ChIJyd3JiWlNFmsR9RUq2ySTTZQ", }, { "location": { "latitude": -35.283054, "longitude": 149.1290996 }, "placeId": "ChIJyd3JiWlNFmsR9RUq2ySTTZQ", }, { "location": { "latitude": -35.2830794, "longitude": 149.1290094 }, "placeId": "ChIJyd3JiWlNFmsR9RUq2ySTTZQ", }, { "location": { "latitude": -35.2830794, "longitude": 149.1290094 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.28313383700836, "longitude": 149.12893500604946 }, "originalIndex": 6, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283134499999996, "longitude": 149.12893409999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283190399999995, "longitude": 149.1288668 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2832503, "longitude": 149.1288041 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2833133, "longitude": 149.1287463 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2833794, "longitude": 149.128694 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283448299999996, "longitude": 149.128647 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2835199, "longitude": 149.1286054 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2835934, "longitude": 149.1285699 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.283668899999995, "longitude": 149.12854059999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.28372649999999, "longitude": 149.1285237 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.28386179999999, "longitude": 149.12849319999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2839978, "longitude": 149.1284682 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2840205, "longitude": 149.12846779999998 }, "placeId": "ChIJWSb8ImpNFmsRp_4JAxJFE1A", }, { "location": { "latitude": -35.2840205, "longitude": 149.12846779999998 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.2840524, "longitude": 149.12845969999998 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.284341500000004, "longitude": 149.1284124 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.2843875, "longitude": 149.1284034 }, "placeId": "ChIJZe8tFWpNFmsR4brZ1vldk2E", }, { "location": { "latitude": -35.2843875, "longitude": 149.1284034 }, "placeId": "ChIJVx7Ta2pNFmsRx9OI9CnN5tI", }, { "location": { "latitude": -35.2845916, "longitude": 149.1283726 }, "placeId": "ChIJVx7Ta2pNFmsRx9OI9CnN5tI", }, { "location": { "latitude": -35.2845916, "longitude": 149.1283726 }, "placeId": "ChIJtWxAZmpNFmsRlbUCkc6VtnA", }, { "location": { "latitude": -35.28459730000001, "longitude": 149.1283703 }, "placeId": "ChIJtWxAZmpNFmsRlbUCkc6VtnA", }, { "location": { "latitude": -35.284728747199374, "longitude": 149.12834860726772 }, "originalIndex": 7, "placeId": "ChIJtWxAZmpNFmsRlbUCkc6VtnA", }, ], }
回應使用下列結構定義。
SnapToRoadsResponse
Field | Required | Type | Description |
---|---|---|---|
| optional | Array<SnappedPoint> | An array of snapped points. See SnappedPoint for more information. |
| optional | string | A string containing a user-visible warning. |
SnappedPoint
Field | Required | Type | Description |
---|---|---|---|
| required | LatitudeLongitudeLiteral | See LatitudeLongitudeLiteral for more information. |
| required | string | A unique identifier for a place. All place IDs returned by the Roads API correspond to road segments. |
| optional | number |
An integer that indicates the corresponding value in the original
request. Each value in the request should map to a snapped value in
the response. However, if you've set interpolate=true or if you're
using nearest roads, then it's possible that the response will
contain more coordinates than the request. Interpolated values will
not have an |
LatitudeLongitudeLiteral
An object describing a specific location with Latitude and Longitude in decimal degrees.
Field | Required | Type | Description |
---|---|---|---|
| required | number | Latitude in decimal degrees |
| required | number | Longitude in decimal degrees |
示範
- 在地圖上按一下即可建立車輛軌跡。請注意,如果點之間距離過遠,可能無法正確對齊。
- 按兩下即可將歷程對齊道路。
查看全螢幕範例。
JavaScript
var apiKey = 'YOUR_API_KEY_HERE'; var map; var drawingManager; var placeIdArray = []; var polylines = []; var snappedCoordinates = []; function initialize() { var mapOptions = { zoom: 17, center: {lat: -33.8667, lng: 151.1955,} }; map = new google.maps.Map(document.getElementById('map'), mapOptions); // Adds a Places search box. Searching for a place will center the map on that // location. map.controls[google.maps.ControlPosition.RIGHT_TOP].push( document.getElementById('bar')); var autocomplete = new google.maps.places.Autocomplete( document.getElementById('autoc')); autocomplete.bindTo('bounds', map); autocomplete.addListener('place_changed', function() { var place = autocomplete.getPlace(); if (place.geometry.viewport) { map.fitBounds(place.geometry.viewport); } else { map.setCenter(place.geometry.location); map.setZoom(17); } }); // Enables the polyline drawing control. Click on the map to start drawing a // polyline. Each click will add a new vertice. Double-click to stop drawing. drawingManager = new google.maps.drawing.DrawingManager({ drawingMode: google.maps.drawing.OverlayType.POLYLINE, drawingControl: true, drawingControlOptions: { position: google.maps.ControlPosition.TOP_CENTER, drawingModes: [ google.maps.drawing.OverlayType.POLYLINE ] }, polylineOptions: { strokeColor: '#696969', strokeWeight: 2, strokeOpacity: 0.3, } }); drawingManager.setMap(map); // Snap-to-road when the polyline is completed. drawingManager.addListener('polylinecomplete', function(poly) { var path = poly.getPath(); polylines.push(poly); placeIdArray = []; runSnapToRoad(path); }); // Clear button. Click to remove all polylines. document.getElementById('clear').addEventListener('click', function(event) { event.preventDefault(); for (var i = 0; i < polylines.length; ++i) { polylines[i].setMap(null); } polylines = []; return false; }); } // Snap a user-created polyline to roads and draw the snapped path function runSnapToRoad(path) { var pathValues = []; for (var i = 0; i < path.getLength(); i++) { pathValues.push(path.getAt(i).toUrlValue()); } $.get('https://roads.googleapis.com/v1/snapToRoads', { interpolate: true, key: apiKey, path: pathValues.join('|') }, function(data) { processSnapToRoadResponse(data); drawSnappedPolyline(); }); } // Store snapped polyline returned by the snap-to-road service. function processSnapToRoadResponse(data) { snappedCoordinates = []; placeIdArray = []; for (var i = 0; i < data.snappedPoints.length; i++) { var latlng = new google.maps.LatLng( data.snappedPoints[i].location.latitude, data.snappedPoints[i].location.longitude); snappedCoordinates.push(latlng); placeIdArray.push(data.snappedPoints[i].placeId); } } // Draws the snapped polyline (after processing snap-to-road response). function drawSnappedPolyline() { var snappedPolyline = new google.maps.Polyline({ path: snappedCoordinates, strokeColor: '#add8e6', strokeWeight: 4, strokeOpacity: 0.9, }); snappedPolyline.setMap(map); polylines.push(snappedPolyline); } $(window).load(initialize);
JavaScript + HTML
<!DOCTYPE html> <html> <head> <meta name="viewport" content="initial-scale=1.0, user-scalable=no"> <meta charset="utf-8"> <title>Roads API Demo</title> <style> html, body, #map { height: 100%; margin: 0px; padding: 0px } #panel { position: absolute; top: 5px; left: 50%; margin-left: -180px; z-index: 5; background-color: #fff; padding: 5px; border: 1px solid #999; } #bar { width: 240px; background-color: rgba(255, 255, 255, 0.75); margin: 8px; padding: 4px; border-radius: 4px; } #autoc { width: 100%; box-sizing: border-box; } </style> <script src="https://www.gstatic.com/external_hosted/jquery2.min.js"></script> <script src="https://maps.googleapis.com/maps/api/js?libraries=drawing,places&key=YOUR_API_KEY"></script> <script> var apiKey = 'YOUR_API_KEY_HERE'; var map; var drawingManager; var placeIdArray = []; var polylines = []; var snappedCoordinates = []; function initialize() { var mapOptions = { zoom: 17, center: {lat: -33.8667, lng: 151.1955,} }; map = new google.maps.Map(document.getElementById('map'), mapOptions); // Adds a Places search box. Searching for a place will center the map on that // location. map.controls[google.maps.ControlPosition.RIGHT_TOP].push( document.getElementById('bar')); var autocomplete = new google.maps.places.Autocomplete( document.getElementById('autoc')); autocomplete.bindTo('bounds', map); autocomplete.addListener('place_changed', function() { var place = autocomplete.getPlace(); if (place.geometry.viewport) { map.fitBounds(place.geometry.viewport); } else { map.setCenter(place.geometry.location); map.setZoom(17); } }); // Enables the polyline drawing control. Click on the map to start drawing a // polyline. Each click will add a new vertice. Double-click to stop drawing. drawingManager = new google.maps.drawing.DrawingManager({ drawingMode: google.maps.drawing.OverlayType.POLYLINE, drawingControl: true, drawingControlOptions: { position: google.maps.ControlPosition.TOP_CENTER, drawingModes: [ google.maps.drawing.OverlayType.POLYLINE ] }, polylineOptions: { strokeColor: '#696969', strokeWeight: 2, strokeOpacity: 0.3, } }); drawingManager.setMap(map); // Snap-to-road when the polyline is completed. drawingManager.addListener('polylinecomplete', function(poly) { var path = poly.getPath(); polylines.push(poly); placeIdArray = []; runSnapToRoad(path); }); // Clear button. Click to remove all polylines. document.getElementById('clear').addEventListener('click', function(event) { event.preventDefault(); for (var i = 0; i < polylines.length; ++i) { polylines[i].setMap(null); } polylines = []; return false; }); } // Snap a user-created polyline to roads and draw the snapped path function runSnapToRoad(path) { var pathValues = []; for (var i = 0; i < path.getLength(); i++) { pathValues.push(path.getAt(i).toUrlValue()); } $.get('https://roads.googleapis.com/v1/snapToRoads', { interpolate: true, key: apiKey, path: pathValues.join('|') }, function(data) { processSnapToRoadResponse(data); drawSnappedPolyline(); }); } // Store snapped polyline returned by the snap-to-road service. function processSnapToRoadResponse(data) { snappedCoordinates = []; placeIdArray = []; for (var i = 0; i < data.snappedPoints.length; i++) { var latlng = new google.maps.LatLng( data.snappedPoints[i].location.latitude, data.snappedPoints[i].location.longitude); snappedCoordinates.push(latlng); placeIdArray.push(data.snappedPoints[i].placeId); } } // Draws the snapped polyline (after processing snap-to-road response). function drawSnappedPolyline() { var snappedPolyline = new google.maps.Polyline({ path: snappedCoordinates, strokeColor: '#add8e6', strokeWeight: 4, strokeOpacity: 0.9, }); snappedPolyline.setMap(map); polylines.push(snappedPolyline); } $(window).load(initialize); </script> </head> <body> <div id="map"></div> <div id="bar"> <p class="auto"><input type="text" id="autoc"/></p> <p><a id="clear" href="#">Click here</a> to clear map.</p> </div> </body> </html>