BARGE TRAFFIC CONGESTION ON US INLAND WATERWAYS OCCURS PRIMARILY AT LOCKS. LOCK CAPACITY ANALYSIS MUST DEAL WITH ESTIMATION OF DELAYS AT VARIOUS TRAFFIC LEVELS. THE M/M/1 QUEUEING MODEL HAS BEEN PROPOSED FOR SUCH ANALYSIS, BUT IT IS SHOWN THAT LOCK OPERATIONS DO NOT CORRESPOND WELL TO M/M/1 MODEL ASSUMPTIONS AND, FURTHER, THAT THE MODEL DOES A POOR JOB OF PREDICTING DELAYS. THE ASSUMPTIONS OF M/G/1 DO CORRESPOND WELL WITH THE OPERATION OF MANY SINGLE-CHAMBER LOCKS, AND THE DELAY PREDICTIONS OF THIS MODEL AQREE WELL WITH SIMULATION RESULTS. FOR TWO-CHAMBER (PARALLEL) LOCKS, NO EXACT QUEUEING RESULTS ARE AVAILABLE. CALCULATED NUMERICAL VALUES REVEAL THAT KNOWN UPPER AND LOWER BOUNDS ON MEAN DELAYS ARE NOT TIGHT ENOUGH TO BE OF PRACTICAL USE AT THE TRAFFIC LEVELS OF INTEREST.(Author/publisher).
Samenvatting