Turn Angles in OSRM were computed using a lookahead of 10 meters.

This PR adds more advanced coordinate extraction, analysing the road
to detect offsets due to OSM way modelling.

In addition it improves the handling of bearings. Right now OSM reports
bearings simply based on the very first coordinate along a way.
With this PR, we store the bearings for a turn correctly, making the
bearings for turns correct.

profiles/bicycle.lua

@@ -395,7 +395,7 @@ function way_function (way, result)
   end
 
   -- set the road classification based on guidance globals configuration
-  set_classification(highway,result)
+  set_classification(highway,result,way)
 
   -- maxspeed
   limit( result, maxspeed, maxspeed_forward, maxspeed_backward )

profiles/car.lua

@@ -425,7 +425,7 @@ function way_function (way, result)
   end
 
   -- set the road classification based on guidance globals configuration
-  set_classification(highway,result)
+  set_classification(highway,result,way)
 
   -- parse the remaining tags
   local name = way:get_value_by_key("name")

profiles/lib/guidance.lua

@@ -42,7 +42,7 @@ road_types = { ["motorway"] = true,
 
 link_types = { ["motorway_link"] = true, ["trunk_link"] = true, ["primary_link"] = true, ["secondary_link"] = true, ["tertiary_link"] = true }
 
-function Guidance.set_classification (highway, result)
+function Guidance.set_classification (highway, result, input_way)
     if motorway_types[highway] then
         result.road_classification.motorway_class = true;
     end
@@ -59,6 +59,33 @@ function Guidance.set_classification (highway, result)
     else
         result.road_classification.may_be_ignored = true;
     end
+
+    local lane_count = input_way:get_value_by_key("lanes")
+    if lane_count and lane_count ~= "" then
+        local lc = tonumber(lane_count)
+        if lane_count ~= nil then
+            result.road_classification.num_lanes = lc
+        end
+    else
+        local total_count = 0
+        local forward_count = input_way:get_value_by_key("lanes:forward")
+        if forward_count and forward_count ~= "" then
+            local fc = tonumber(forward_count)
+            if fc ~= nil then
+                total_count = fc
+            end
+        end
+        local backward_count = input_way:get_value_by_key("lanes:backward")
+        if backward_count and backward_count ~= "" then
+            local bc = tonumber(backward_count)
+            if bc ~= nil then
+                total_count = total_count + bc
+            end
+        end
+        if total_count ~= 0 then
+            result.road_classification.num_lanes = total_count
+        end
+    end
 end
 
 -- returns forward,backward psv lane count
@@ -69,19 +96,19 @@ local function get_psv_counts(way)
 
     local fw = 0;
     local bw = 0;
-    if( psv and psv ~= "" ) then
+    if  psv and psv ~= ""  then
         fw = tonumber(psv)
         if( fw == nil ) then
             fw = 0
         end
-    end 
-    if( psv_forward and psv_forward ~= "" ) then
+    end
+    if psv_forward and psv_forward ~= "" then
         fw = tonumber(psv_forward)
         if( fw == nil ) then
             fw = 0
         end
-    end 
-    if( psv_backward and psv_backward ~= "" ) then
+    end
+    if psv_backward and psv_backward ~= "" then
         bw = tonumber(psv_backward);
         if( bw == nil ) then
             bw = 0