NLR developed a Taxiway Conflict Detection tool using probability trees to determine possible conflict pairs. The algorithm has been implemented in NARSIM Tower and connected to NASA Ames FFC for carrying out simulations of Charlotte Douglas airport by FAA apron controllers.

The TCD tool was also used for validation at Schiphol Airport, where the main requirement of the by ATC provider was to include the controller in the taxi route selection process and use that information as an additional TCD input. NLR enhanced the existing aircraft state and airport layout dependent TCD prototype with planning information for Schiphol Airport. Variable Taxi Time Calculation and a traffic density estimator were added to determine the optimal taxi route for aircraft taking traffic density into account.