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58 Circulation elements provide the necessary public, non-public, and sterile links to tie the func- tional elements of the terminal together. Secure Circulation Secure circulation typically consists of the main corridor of the concourses, plus the security checkpoints. Concourses are typically either single loaded (gates on one side) or double loaded (gates on both sides). Single-loaded concourses can also have concessions and other uses on the non-gate side which may cause them to function more like double-loaded concourses. Corridor width is a function of single/double loading, the presence of moving walkways, passenger vol- umes, and hubbing activity. As shown in Figure 71, ancillary uses (such as telephones, water fountains, vending machines, or advertizing displays), and some adjacent activities (FIDS monitors), can effectively reduce the width of a corridor. It is recommended that these uses be recessed into the corridor walls (as shown in Figure 72) to minimize the impact on passenger flow, or their presence taken into account when programming circulation space. The following are recommended minimum clear circulation widths: â¢ For concourses without moving walkways, a corridor 20 feet wide for single-loaded con- courses and 30 feet wide for double-loaded concourses is recommended. This width is gener- ally adequate for most medium- to high-volume concourses used primarily for O&D flights, or for shorter hub concourses. â¢ For concourses with moving walkways, a 15-foot corridor is recommended on each side of the moving walkway. This width generally allows for bidirectional movement on both sides. Wider corridors may be required for high-volume hubbing terminals. If a significant number of electric carts are in use, this width would also require a wider clear circulation aisle. FIS Sterile Arrivals Circulation Sterile circulation consists of the corridors and vertical circulation elements that connect the international arrivals gates to the FIS facilities. In some terminals a portion of the sterile corri- dor system may involve âedgeâ corridors that connect multiple gates to a vertical circulation core or directly to the FIS. These edge corridors must have controlled isolation doors to prevent inter- national arriving passengers from mixing with departing passengers. Because sterile corridors have single-direction passenger flow, they can be narrower than the main concourse corridors. Typically, a 15- to 20-foot-wide corridor will allow a single-direction Concourse Circulation Model
Concourse Circulation Model 59 Source: The Apron & Terminal Building Planning Manual, The Ralph M. Parsons Company, pg. 3â17. Figure 71. Effects of ancillary uses on effective concourse width. moving walkway for most terminals depending on the number of gates and peak period arrivals. Edge sterile corridors are typically 8 to 10 feet wide (clear width). The program area must also include vertical circulation from the holdroom level to the sterile corridor, if it is on a separate level. The total circulation area can be based on an area per equivalent concourse length. This length is determined by gates as expressed in NBEG. The actual amount of secure circulation required will depend on the terminal configuration and should consider whether gates are
60 Airport Passenger Terminal Planning and Design single or double loaded. Exit and service stairs to the apron level should be included in the secure circulation area. The spreadsheet model was developed to estimate the circulation dimensions using the NBEG approach. This model will function in the same manner as the other spreadsheet models with links to the Table of Contents and the Userâs Guide, and the use of color-coded cells for consistency as seen in Figure 73. The approach used in the model is based on estimating the length of a concourse using the planned gate mix as expressed in NBEG. The NBEG gate mix is converted to a gate frontage by assum- ing typical wingtip clearances. The user then makes assumptions as to concourse configuration to estimate the gross circulation areas. There are a number of different circulation areas that can be addressed. The single-concourse estimate is used in the model to show the basic approach and the lessons learned can then be adapted to other areas of circulation that are more dependent on local design and use. The model has three basic functions: to determine the suggested circulation corridor width, to determine the NBEG of the concourse to estimate frontage and overall length, and then to calculate and compare the existing circulation area. Figure 74 is a screen print of the model, showing that the comparison of existing width and area in this example are âLess than Suggestedâ based on the model inputs. On line 8 of the model, as seen in Figure 75, the user is asked to input a percentage factor for concourses that support an airline hub. The comment for this input suggests a small 5% to 10% range that will add to the suggested corridor width. In most cases this factor can be left at 0%. However, at the largest and busiest airports, the sheer volume of passengers that may enplane or deplane during the peak periods, or the major cross-flows that may occur during the peak transfer times at large hubs, may require more than the normally suggested corridor width. Figure 73. Concourse Circulation model. Figure 72. Example of recessing ancillary facilities.
The model asks the user to select inputs that describe the concourse in question. On Line 10, the input is whether or not moving walkways are used. If the user selects Yes from the drop down list, the next input on Line 11 must be either Narrow Width or Wide Width. If the dash is selected, a Choice Error message will appear to prompt a correction. Inversely, if No is selected from the list on Line 10 and then Narrow Width or Wide Width is selected on Line 11, the Choice Error message will also appear until the dash is selected, as seen in Figure 76. The model prompts the user to move down to Line 31 and input the number of gates that exist on the concourse for specific design aircraft classes in order to compute the NBEG. The NBEG will be calculated in cell E40 which is linked back to cell C14 as seen in Figure 77. The next inputs that the user needs to make in the model are on Lines 15 and 16. A usage per- centage is requested to describe the allocation of the end space on the concourse. If the concourse circulation runs to the end of the concourse with no space used for holdrooms or amenities, then Figure 74. Example of comparison of suggested and existing width and area. Figure 75. Example of Secure Circulation tab. Concourse Circulation Model 61
62 Airport Passenger Terminal Planning and Design the usage percentage should be 100%. Depending on how the end space is used and how much area is taken away from circulation for holdrooms, the usage percentage may be as low as 80%. An assessment of the concourse gate allocation and loading structure will help determine what percentage to use. Typically 85% is a good starting point for linear pier concourse design. Moving Walkways Moving walks transport passengers and their baggage on a moving platform horizontally or at slight inclines. This system can either be manufactured as a pallet or moving belt style. A series of continuous flat metal plates jointed together in a horizontal manner to form the walk- way describes the pallet system. The moving belt style consists of a series of metal rollers over which a rubber walking surface is placed, sometimes resulting in a bouncy feel when walking over the surface. As a general planning standard, moving walkways are typically recommended when walking distances exceed approximately 1,000 feet between the major functions of the terminal complex. These walkways may be utilized from parking facilities to ticketing/baggage claim areas, as access to ground transportation stations, in connectors between concourse/terminal to terminal, and security screening checkpoints to major concourse nodes and/or the furthest concourse gate. When planning for moving walkways, factors that influence the layout consist of the volume of passengers to be transported, whether concourses are single or double loaded, and locations of major concessions nodes. Moving walkways are typically installed in pairs traveling in opposite directions and designated by pallet widths or the area the passenger travels on. Depending on the manufacturer, a pallet range for an airport moving walkway is 40 inches to as much as 56 inches, Figure 76. Example of Choice Error message. Figure 77. NBEG calculation matrix.
which allows fast moving passengers to easily pass those standing with little to no interference. The overall required width for the moving walkway ranges from 5 feet 6 inches to 7 feet, and lengths vary between manufacturers. Figure 78 represents a typical moving walkway with common dimensional criteria. The default widths used for double moving walkways are 12 feet and 15 feet, which allows for an additional 1-foot buffer between the two walkways. Figure 78. Dimensional example of a moving walkway. Concourse Circulation Model 63