Add support for DurationInTraffic

src/Google.Maps/Direction/DirectionLeg.cs

@@ -13,6 +13,9 @@ public class DirectionLeg
 
 		[JsonProperty("duration")]
 		public ValueText Duration { get; set; }
+
+		[JsonProperty("duration_in_traffic")]
+		public ValueText DurationInTraffic { get; set; }
 
 		[JsonProperty("distance")]
 		public ValueText Distance { get; set; }

src/Google.Maps/Direction/DirectionRequest.cs

@@ -24,6 +24,15 @@ public class DirectionRequest : BaseRequest
 		[DefaultValue(TravelMode.driving)]
 		public TravelMode Mode { get; set; }
 
+
+		/// <summary>
+		/// Specifies the assumptions to use when calculating time in traffic. This setting affects the value returned in the duration_in_traffic field in the response,
+		/// which contains the predicted time in traffic based on historical averages. The traffic_model parameter may only be specified for driving directions where
+		/// the request includes a departure_time, and only if the request includes an API key or a Google Maps Platform Premium Plan client ID. 
+		/// </summary>
+		[DefaultValue(TrafficModel.best_guess)]
+		public TrafficModel TrafficModel { get; set; }
+
 		/// <summary>
 		/// (optional) Directions may be calculated that adhere to certain restrictions.
 		/// </summary>
@@ -119,6 +128,7 @@ public override Uri ToUri()
 				.Append("origin", (Origin == null ? (string)null : Origin.GetAsUrlParameter()))
 				.Append("destination", (Destination == null ? (string)null : Destination.GetAsUrlParameter()))
 				.Append("mode", (Mode != TravelMode.driving ? Mode.ToString() : (string)null))
+				.Append("traffic_model", (TrafficModel!=TrafficModel.best_guess ? TrafficModel.ToString():(string)null))
 				.Append("departure_time", (DepartureTime == null ? null : DepartureTime.Value.ToString()))
 				.Append("arrival_time", (ArrivalTime == null ? null : ArrivalTime.Value.ToString()))
 				.Append("waypoints", WaypointsToUri())

src/Google.Maps/Google.Maps.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>net461;netstandard1.3</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>sn.snk</AssemblyOriginatorKeyFile>
     <GenerateAssemblyInfo>False</GenerateAssemblyInfo>
@@ -10,9 +10,6 @@
     <DefineConstants>HAS_SYSTEMDRAWING</DefineConstants>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="10.0.3" />
-  </ItemGroup>
-  <ItemGroup>
-    <Reference Include="System.Net.Http" />
+    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
   </ItemGroup>
 </Project>

src/Google.Maps/TrafficModel.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Google.Maps {
+	/// <summary>
+	/// Specifies the assumptions to use when calculating time in traffic. This setting affects the value returned in the duration_in_traffic field in the response,
+	/// which contains the predicted time in traffic based on historical averages. The traffic_model parameter may only be specified for driving directions where
+	/// the request includes a departure_time, and only if the request includes an API key or a Google Maps Platform Premium Plan client ID. 
+	/// </summary>
+	/// <see href="http://code.google.com/apis/maps/documentation/directions/#traffic_model"/>
+	public enum TrafficModel {
+		/// <summary>
+		/// (default) indicates that the returned duration_in_traffic should be the best estimate of travel time given what is known about both historical
+		/// traffic conditions and live traffic. Live traffic becomes more important the closer the departure_time is to now.
+		/// </summary>
+		best_guess,
+
+		/// <summary>
+		///  indicates that the returned duration_in_traffic should be longer than the actual travel time on most days, though occasional days with particularly bad traffic conditions may exceed this value
+		/// </summary>
+		pessimistic,
+
+		/// <summary>
+		/// indicates that the returned duration_in_traffic should be shorter than the actual travel time on most days, though occasional days with particularly good traffic conditions may be faster than this value.
+		/// </summary>
+		optimistic,
+
+	}
+}