Figure 1: Current south-side Los Angeles International Airport (LAX) layout
Figure 2: Modified south-side LAX layout, showing center taxiway
Introduction:
In June 2003, LAX returned to FutureFlight Central to simulate a center taxiway between Runways 25R and 25L, one of the options the airport is studying as part of its modernization plan (http://www.laxmasterplan.org/). HNTB is the consultant for this study, which is aimed at reducing runway incursions.
The most common runway incursions at LAX have occurred when an aircraft arriving on Runway 25L exits at one of the high-speed exits, and then fails to stop before overshooting the hold-short bars for Runway 25R. The intent of the center taxiway concept is to force aircraft to turn onto a parallel center taxiway, thus eliminating the straight shot to Runway 25R that exists on the current high-speed exits. The center taxiway would also provide controllers more options for holding and crossing arriving aircraft, especially during peak traffic periods.
In order to meet FAA requirements for separation between a runway and a parallel taxiway, FutureFlights virtual model of LAX moved Runway 25L 50 feet to the south to make room for the center taxiway between the two runways.
The objective of the study was to evaluate a new center taxiway at Los Angeles International Airport (LAX) on the South Airfield between Runways 25R and 25L. This study is an extension of the runway incursion studies conducted at FutureFlight Central in February and April 2001.
Some of the key aspects of the simulation are the following:
The existing 3-D visual database was modified to include a center taxiway and associated connecting taxiways between Runways 25L and 25R.
The north and south sides of LAX were simulated.
Traffic scenarios were the same as run in 2001, reflecting pre-9/11/2001 traffic conditions.
Traffic was run under full visibility and reduced visibility conditions (VMC and IMC)
Four certified FAA controllers from the LAX tower participated.
Combined arrival and departure rates ranged from 145 to 161 operations per hour.
Since the center taxiway is conceptual, operational rules had to be developed for the simulation. Working together, HNTB, NATCA (National Air Traffic Controllers Association), the FAA, and FutureFlight personnel defined the operational rules by which to manage the traffic on the south-side airfield.
LAX reduced the risk of unnecessary development costs by trying out the proposed center taxiway design with the users before investing in expensive construction.
Tower controllers refined the operational procedures for managing center taxiway traffic.
LAX tested the proposed configuration with traffic representative of future heavier demand.
Virtual reality provided a platform for collaboration between airport managers, airfield operators, and FAA officials.
If the designers build it and we can land and depart with the largest aircraft in the world holding in-between the runways, its going to be fantastic. You can see how its going to eliminate runway incursions.
Anonymous LAX Tower Controller
The simulation, [LAX Phase III], went on flawlessly, professionally and on schedule.
Andres Garcia, Project Manager, HNTB Corporation
The data indicated that, while workload is an issue for the ground control position, the concept of a center taxiway would be viable for reducing runway incursions.