public IReadOnlyList<FunctionBarrier> FunctionBarriers {get; set;}

// Create a NetworkAttribute object for the Shape length network attribute from the UtilityNetworkDefinition
using (NetworkAttribute shapeLengthNetworkAttribute = utilityNetworkDefinition.GetNetworkAttribute("Shape length"))
{
  // Create a function that adds up shape length
  Add lengthFunction = new Add(shapeLengthNetworkAttribute);

  // Create a function barrier that stops traversal after 1000 feet
  FunctionBarrier distanceBarrier = new FunctionBarrier(lengthFunction, Operator.GreaterThan, 1000.0);

  // Set this function barrier
  traceConfiguration.Traversability.FunctionBarriers = new List<FunctionBarrier>() { distanceBarrier };
}