diff --git a/routing/edge_estimator.cpp b/routing/edge_estimator.cpp
index d929ccbc8a..9d6f3c48f4 100644
--- a/routing/edge_estimator.cpp
+++ b/routing/edge_estimator.cpp
@@ -10,6 +10,10 @@ namespace
 {
 double CalcTrafficFactor(SpeedGroup speedGroup)
 {
+  double constexpr kImpossibleDrivingFactor = 1e4;
+  if (speedGroup == SpeedGroup::TempBlock)
+    return kImpossibleDrivingFactor;
+
   double const percentage =
       0.01 * static_cast<double>(kSpeedGroupThresholdPercentage[static_cast<size_t>(speedGroup)]);
   CHECK_GREATER(percentage, 0.0, ("Speed group:", speedGroup));
diff --git a/traffic/speed_groups.hpp b/traffic/speed_groups.hpp
index 91f81786d4..9942d5e93f 100644
--- a/traffic/speed_groups.hpp
+++ b/traffic/speed_groups.hpp
@@ -37,6 +37,7 @@ static_assert(static_cast<uint8_t>(SpeedGroup::Count) <= 8, "");
 // special groups where V is unknown or not defined.
 extern uint32_t const kSpeedGroupThresholdPercentage[static_cast<size_t>(SpeedGroup::Count)];
 
+/// \note This method is used while traffic jam generation.
 SpeedGroup GetSpeedGroupByPercentage(double p);
 
 string DebugPrint(SpeedGroup const & group);