Roads API 會擷取路徑上最多 100 個 GPS 點,並傳回類似的資料集,其中的點會對應到車輛最有可能行駛的道路。您可以選擇要求插補點,產生平滑的路徑,貼合道路幾何圖形。
要求
您必須使用 HTTPS,以以下形式傳送要求,將座標點對齊道路:
https://roads.googleapis.com/v1/snapToRoads?parameters&key=YOUR_API_KEY必要參數
-
路徑
要對齊的路徑。路徑參數接受經緯度組合清單。緯度和經度值應以半形逗號分隔。座標應以直立線字元「|」分隔。例如:
path=60.170880,24.942795|60.170879,24.942796|60.170877,24.942796。注意:如果點之間的距離太遠,對齊演算法可能無法順利運作。如果發現奇怪的對齊行為,請嘗試建立點與點之間距離較近的路徑。為確保路徑貼合道路的品質最佳,您應盡量提供連續點對之間距離在 300 公尺以內的路徑。這也有助於處理因 GPS 訊號中斷或雜訊,導致連續點之間出現的任何孤立長跳躍。
選用參數
-
內插
是否要插補路徑,以納入構成完整道路幾何的所有點。如果為 true,系統也會傳回其他內插點,因此產生的路徑會平滑地沿著道路幾何圖形,即使是轉彎和穿過隧道也一樣。內插路徑很可能包含比原始路徑更多的點。預設值為
false。
範例
下列要求會將指定點對齊道路幾何。這組特定資料會沿著環形道路移動;設定 interpolate=true 可讓傳回的幾何圖形符合道路的彎曲度。使用 interpolate=false 時,路徑仍會貼齊道路,但產生的折線不會那麼平滑。
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
對於每個有效要求,Roads API 會以要求網址中指定的格式傳回回應,例如下列 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", }, ], }
回應會使用下列結構定義。
SnapToRoadsResponse
| 欄位 | 必填 | 類型 | 說明 |
|---|---|---|---|
|
選用 | Array<SnappedPoint> |
已對齊的點陣列。 詳情請參閱 SnappedPoint。 |
|
選用 | 字串 |
包含使用者可見警告的字串。 |
SnappedPoint
| 欄位 | 必填 | 類型 | 說明 |
|---|---|---|---|
|
required | LatitudeLongitudeLiteral | 詳情請參閱 LatitudeLongitudeLiteral。 |
|
required | 字串 |
地點的專屬 ID。Roads API 傳回的所有地點 ID 都對應至路段。 |
|
選用 | 數字 |
整數,表示原始要求中的對應值。要求中的每個值都應對應至回應中的對齊值。不過,如果您已設定 interpolate=true 或使用最鄰近的道路,回應可能包含比要求更多的座標。內插值不會有 |
LatitudeLongitudeLiteral
這個物件會以十進制度數描述特定位置的經緯度。
| 欄位 | 必填 | 類型 | 說明 |
|---|---|---|---|
|
required | 數字 |
以十進制度數表示的緯度 |
|
required | 數字 |
以十進制度數表示的經度 |
示範
- 在地圖上點按多個點來建立車輛軌跡,請注意,如果點太遠,可能無法正確對齊。
- 按兩下即可將路線貼齊道路。
在全螢幕模式中查看這個範例。
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>