diff --git a/VectoCore/VectoCore/OutputData/IModalDataContainer.cs b/VectoCore/VectoCore/OutputData/IModalDataContainer.cs
index 3239ca696771a6f31f7b2318c3274346d07d5ba0..33ccd8bad6f259b4e513368c527ace75905ece1c 100644
--- a/VectoCore/VectoCore/OutputData/IModalDataContainer.cs
+++ b/VectoCore/VectoCore/OutputData/IModalDataContainer.cs
@@ -200,7 +200,7 @@ namespace TUGraz.VectoCore.OutputData
 		public static Scalar CruiseTimeShare(this MeterPerSquareSecond[] acceleration3SecondAverage)
 		{
 			if (acceleration3SecondAverage.Length > 0) {
-				return 100.SI<Scalar>() * acceleration3SecondAverage.Count(x => x.IsBetween(-0.125, -0.125)) /
+				return 100.SI<Scalar>() * acceleration3SecondAverage.Count(x => x.IsBetween(-0.125, 0.125)) /
 						acceleration3SecondAverage.Length;
 			}
 			return null;
diff --git a/VectoCore/VectoCore/OutputData/SummaryDataContainer.cs b/VectoCore/VectoCore/OutputData/SummaryDataContainer.cs
index 87be1e16ff201f720c42f9bfbedf142c113f7db9..48c3978c90cb3ab5eac575ae6d81890cb50cebbf 100644
--- a/VectoCore/VectoCore/OutputData/SummaryDataContainer.cs
+++ b/VectoCore/VectoCore/OutputData/SummaryDataContainer.cs
@@ -275,10 +275,21 @@ namespace TUGraz.VectoCore.OutputData
 			row[ACC] = modData.AccelerationAverage();
 			row[ACC_POS] = acc.AccelerationsPositive();
 			row[ACC_NEG] = acc.AccelerationsNegative();
-			row[ACC_TIMESHARE] = acc.AccelerationTimeShare();
-			row[DEC_TIMESHARE] = acc.DecelerationTimeShare();
-			row[CRUISE_TIMESHARE] = acc.CruiseTimeShare();
+			var accTimeShare = acc.AccelerationTimeShare();
+			row[ACC_TIMESHARE] = accTimeShare;
+			var decTimeShare = acc.DecelerationTimeShare();
+			row[DEC_TIMESHARE] = decTimeShare;
+			var cruiseTimeShare = acc.CruiseTimeShare();
+			row[CRUISE_TIMESHARE] = cruiseTimeShare;
 			row[STOP_TIMESHARE] = modData.StopTimeShare();
+
+			var shareSum = accTimeShare + decTimeShare + cruiseTimeShare;
+			if (!shareSum.IsEqual(100)) {
+				Log.Error(
+					"Sumfile Error: driving behavior timeshares must sum up to 100%: acc: {0}%, dec: {1}%, cruise: {2}%, sum: {3}%",
+					accTimeShare.ToOutputFormat(1, null, false), decTimeShare.ToOutputFormat(1, null, false),
+					cruiseTimeShare.ToOutputFormat(1, null, false), shareSum.ToOutputFormat(1, null, false));
+			}
 		}
 
 		private static string ReplaceNotAllowedCharacters(string text)