Removing more slight turns in case if other roads has less highway class.

2 files changed, 11 insertions, 8 deletions

diff --git a/routing/routing_integration_tests/turn_test.cpp b/routing/routing_integration_tests/turn_test.cpp
index dd0b92a41e..daa6ff8d97 100644
--- a/routing/routing_integration_tests/turn_test.cpp
+++ b/routing/routing_integration_tests/turn_test.cpp
@@ -232,11 +232,10 @@ UNIT_TEST(RussiaMoscowParallelResidentalUTurnAvoiding)
   IRouter::ResultCode const result = routeResult.second;
 
   TEST_EQUAL(result, IRouter::NoError, ());
-  integration::TestTurnCount(route, 3 /* expectedTurnCount */);
+  integration::TestTurnCount(route, 2 /* expectedTurnCount */);
   // Checking a turn in case going from a not-link to a link
   integration::GetNthTurn(route, 0).TestValid().TestDirection(CarDirection::TurnLeft);
-  integration::GetNthTurn(route, 1).TestValid().TestDirection(CarDirection::GoStraight);
-  integration::GetNthTurn(route, 2).TestValid().TestDirection(CarDirection::TurnLeft);
+  integration::GetNthTurn(route, 1).TestValid().TestDirection(CarDirection::TurnLeft);
 }
 
 UNIT_TEST(RussiaMoscowPankratevskiPerBolshaySuharedskazPloschadTurnTest)
@@ -892,9 +891,8 @@ UNIT_TEST(RussiaMoscowTTKToNMaslovkaTest)
   IRouter::ResultCode const result = routeResult.second;
 
   TEST_EQUAL(result, IRouter::NoError, ());
-  integration::TestTurnCount(route, 2 /* expectedTurnCount */);
+  integration::TestTurnCount(route, 1 /* expectedTurnCount */);
   integration::GetNthTurn(route, 0).TestValid().TestDirection(CarDirection::ExitHighwayToRight);
-  integration::GetNthTurn(route, 1).TestValid().TestDirection(CarDirection::GoStraight);
 }
 
 UNIT_TEST(RussiaMoscowComplicatedTurnTest)
diff --git a/routing/turns_generator.cpp b/routing/turns_generator.cpp
index d6af46f465..d10d8036f7 100644
--- a/routing/turns_generator.cpp
+++ b/routing/turns_generator.cpp
@@ -150,9 +150,14 @@ bool KeepTurnByHighwayClass(CarDirection turn, TurnCandidates const & possibleTu
   if (minClassForTheRoute == ftypes::HighwayClass::Undefined)
     return false; // Fake edges have HighwayClass::Undefined.
 
-  int const kMaxHighwayClassDiffToKeepTheTurn = 2;
-  if (static_cast<int>(maxClassForPossibleTurns) - static_cast<int>(minClassForTheRoute) >=
-      kMaxHighwayClassDiffToKeepTheTurn)
+  // Maximum difference between HighwayClasses of route segments and possible way segments
+  // to keep the bifurcation point as a turn.
+  int constexpr kMaxHighwayClassDiff = 2;
+  int constexpr kMaxHighwayClassDiffForService = 1;
+  int const diff =
+      static_cast<int>(maxClassForPossibleTurns) - static_cast<int>(minClassForTheRoute);
+  if (diff >= kMaxHighwayClassDiff ||
+      (maxClassForPossibleTurns == ftypes::HighwayClass::Service && diff >= kMaxHighwayClassDiffForService))
   {
     // The turn shall be removed if the route goes near small roads without changing the direction.
     return false;