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64 fewer as any double parking severely restricts through traffic. Unusable Curbside Roadway Geometry Similar restrictions also occur when vehicles are allowed to stop on the inner and outer lanes of a four-lane curbside, leav- Unusable curbside roadway geometries exist when vehicles ing only the two center lanes for through traffic. cannot stop to load or unload passengers because of the curved alignment of the roadway, narrow sidewalks, or other physical obstructions. Many terminals have curved curbside road- Pedestrian Crosswalks ways, but generally the radii of these roads are very large and and Pedestrian Activity motorists do not perceive that they have stopped along a curvi- Pedestrians crossing a curbside roadway restrict the vol- linear section. However, some curbside roadways have small umes of through traffic that can be accommodated. Delays radii or tight curves that hinder a motorist's ability to park par- caused by crosswalks are related to the volume of pedestrians allel to the sidewalk or to enter or exit this space. Motorists may walking across a curbside roadway, the proportion of time be unable to park adjacent to curbsides having narrow side- that pedestrians occupy a crosswalk (properly or improperly), walks (e.g., the ends of island curbside areas) or columns (or and the number of crosswalks located at curbside. Traffic other obstacles) adjacent to the roadways. Large bollards, flows and safety also can be adversely affected by pedestrians which are sometimes placed on terminal building sidewalks to stepping into the roadway to avoid columns or other obsta- protect pedestrians and the terminal building from vehicles cles, hail vehicles, or board/alight from a vehicle stopped in a that may accidentally jump the curb, may interfere with the through lane. ability of motorists to open/close their doors or enter/exit their vehicles. Narrow sidewalks also may force pedestrians to step into Driveways Serving Adjacent Land Uses the roadway (with their baggage) to bypass columns, queues Driveways serving adjacent land uses (e.g., parking lots or of passengers formed at skycap positions, benches, or other rental car ready/return areas) may impede the flow of curbside obstacles. traffic when vehicles in the lane farthest from the terminal decelerate (or accelerate) as they enter (or exit) the driveways Excessive Dwell Times serving the adjacent land uses. Vehicle queues formed at the entrances to these land uses may extend back onto the curb- Excessive dwell times result when vehicles (either private or side roadways. commercial) are allowed to remain at the curbside when not actively loading or unloading passengers. In the case of some commercial vehicle providers, excessive dwell times are per- Insufficient Curb Length mitted by airport rules and regulations. Excessive dwell times Insufficient curb lengths result from curbside demand that may reflect insufficient police presence or visibility, or permis- is greater than 1.3 times the usable curbside length, which also sive airport policies and may occur even if the dwell times of occurs when there is significant double parking. most vehicles are within reasonable limits and fewer than 10% of vehicles remain at the curbside for excessive periods. Inefficient Allocation of Curb Space Potential Curbside Roadway Inefficient allocation of curb space results where the total Improvement Measures available space is adequate to accommodate demand, but the available space has been divided into (or allocated among) Potential curbside roadway improvements to enhance many categories of ground transportation services such that operations are presented for the following categories: some categories are allocated more curb space than required Physical improvements, while others are not allocated enough. This situation may Operational measures, and occur when curb space is allocated to vehicles that rarely serve Policy measures. the airport (e.g., charter buses), demands have changed as a result of the introduction of new services, or the space has been broken into small segments that do not correspond to Physical Improvements to Enhance the operational or maneuverability needs of the assigned class Curbside Operations of ground transportation service. Similarly, inefficient allocation of curb space results when the Widen Curbside Roadways amount of curb associated with a specific airline does not match Additional curbside roadway capacity can be provided by the relative share of passenger traffic served by that airline. the following:

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65 Adding lanes to an existing curbside roadway. Widening a building because passenger terminal building layouts dictate roadway from four lanes to five lanes, for example, can curbside roadway designs (rather than vice versa). A roadway increase through-lane capacity and allow the roadway to that does not match a building's floor elevation would require better accommodate double- or triple-parked vehicles as separate vertical circulation elements to allow passengers to well as the interruption to through traffic caused by vehicles transition between the terminal building and roadway. Con- entering and exiting curbside lanes. sequently, the decision to construct a second-level curbside Constructing new curbside roadway(s) and center island roadway, for example, is driven by the design of a new termi- curbside area. Constructing a second (or third) roadway nal building or planned expansion of an existing terminal parallel to an existing curbside roadway can increase (almost building. double) the capacity of a curbside area. The amount of addi- tional capacity realized from such an improvement is a func- Remove Pedestrian Crosswalks tion of the resulting effective length and the allocation of space. Private vehicle motorists are reluctant to use curb- Additional capacity can result from the following: sides perceived as being less convenient. Customer service and the attractiveness of a curbside waiting area can be Merging crosswalks. Roadway traffic operations can be enhanced by providing weather protection for passengers at improved by merging crosswalks to reduce the number of curbside areas not located immediately adjacent to a termi- locations where vehicular traffic flow is interrupted. Such nal building or under a building canopy. Similarly, shelters changes may reduce the level of service for some pedestrians, with benches can improve the service levels for customers because they would be required to walk farther. In the waiting for scheduled transportation services or courtesy extreme case, it may be necessary to install fences or barriers vehicles. to discourage jaywalking, and potentially to use traffic sig- Constructing a new bypass roadway. At airports with mul- nals or traffic control officers to control pedestrian traffic. tiple terminals, construction of a bypass roadway can reduce Relocating pedestrian traffic. Roadway traffic operations the volume of through traffic on a curbside roadway and can be improved and pedestrian levels of safety enhanced by increase the level of service. constructing pedestrian bridges above, or tunnels beneath, a curbside roadway and removing at-grade pedestrian cross- walks (see Figure 6-4). Since the path would require pedes- Lengthen Curbside Roadway trians to change grades (while transporting baggage), it It may be possible to extend the length of a curbside area past would be necessary to make the new path more attractive the terminal building faade if conveniently located doorways than an alternative at-grade path, or to construct fences or are available to serve motorists using these extensions. Com- other barriers to discourage passengers from continuing to mercial vehicles can be assigned to extended curbside areas, cross the curbside roadway at grade. particularly infrequent users of the airport, such as charter Controlling pedestrian activity. Pedestrians crossing a vehicles. Private vehicle motorists prefer to stop in front of the roadway can automatically activate signals embedded in terminal building and are unlikely to use extended curbside areas unless they are perceived as convenient. Construct Additional Curbside Level At airports with a single-level curbside roadway serving a multilevel terminal building, additional capacity can be pro- vided by constructing a new elevated curbside roadway. For example, in 1984, a second-level curbside roadway was con- structed above the then single-level curbside roadway at Los Angeles International Airport. A second-level curbside road- way also was added at Hartford's Bradley International Air- port. Such a capacity enhancement requires that the terminal building either have multiple levels or be modified concur- rently with the roadway expansion. Generally, it is considered impractical to add capacity by constructing a two-level curbside to serve a single-level build- Figure 6-4. Elevated pedestrian bridge at ing or a three-level curbside to serve a two-level terminal Los Angeles International Airport.

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66 the roadway pavement to improve pedestrian safety and or "intermodal center." Courtyards and dedicated curbside control pedestrian and vehicular traffic flows. roadways can augment the capacity of a curbside area (or relieve congestion) by providing additional passenger pickup (or drop-off) areas. These areas can benefit commer- Provide Alternative Passenger cial vehicle operations as the operators need not maneuver Pickup/Drop-Off Areas through private vehicle traffic to enter and exit their assigned Alternative or supplemental curb space can be developed spaces, and are allowed longer dwell times in these areas. to augment the capacity of the areas adjacent to the terminal Commercial vehicle courtyards are provided at the air- building. Examples of alternative passenger pickup or drop- ports serving Atlanta, Fort Lauderdale, Newark, San Fran- off areas include cisco, and Tampa. The airports serving Denver, Nashville, Orlando, San Francisco, Toronto, and Washington, D.C. Curb space within a parking garage. Several airports have (Dulles) have three-level curbside areas (see Figure 6-6) curbside areas within parking garages allocated for commer- with one entire level reserved for commercial vehicle use. cial ground transportation or private vehicles, or space adja- Although these commercial vehicle areas operate in a man- cent to the garage that is not directly accessible from a ner similar to courtyards, they are not considered potential terminal building. These areas are particularly attractive curbside improvement measures because, as noted earlier, when grade-separated pedestrian access is provided between their implementation requires the appropriate terminal the terminal and the parking structure. Examples include building configuration. A curbside roadway located within a garage allocated to Remote curbsides. At Chicago O'Hare International Air- commercial vehicles (e.g., Seattle-Tacoma International port, commercial vehicles pick up and drop off passengers Airport); on a roadway located between the on-airport hotel and the A commercial vehicle passenger pickup area/curbside central parking garage. Underground tunnels link this site space located at a close-in parking structure away from the (the Transportation Center) to the terminal buildings. An terminal (e.g., Indianapolis International Airport); and enclosed and heated/air conditioned passenger waiting A curbside roadway located within a parking garage area with seating is provided in the parking garage adjacent allocated to private vehicles (e.g., Lambert-St. Louis to the Transportation Center. At San Francisco Inter- International, Salt Lake City International, and national Airport, a supplemental remote curbside is avail- LaGuardia) (see Figure 6-5). able to serve the drivers of private vehicles meeting arriving Commercial vehicle courtyards. A commercial vehicle passengers. This supplemental curbside is located adjacent courtyard is a parking area adjacent to or near the terminal to a remotely located Consolidated Rental Car Facility and building reserved for use by commercial vehicles picking up automated people mover station. The station, intended or dropping off airline passengers. These areas are referred primarily for use by rental car customers, allows passengers to by various terms, such as "ground transportation center" to easily travel to the supplemental remote curbside. Figure 6-5. Supplemental curbside inside parking Figure 6-6. Three-level curbside at San Francisco structure at Salt Lake City International Airport. International Airport.

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67 Operational Measures to Enhance Curbside Capacity Reduce Curbside Requirements The following measures are intended to enhance curbside capacity for certain vehicle modes by reducing the amount of curbside required by other vehicles. Restrict curbside use to authorized vehicles. The use of curbside areas (or portions of curbside areas) can be restricted to authorized commercial ground transportation vehicles. Numerous airport operators limit the use of com- mercial vehicle lanes by posting "authorized vehicles only" signs at the entrance to these lanes, or by installing gate arms activated by AVI transponders, proximity cards, or other Figure 6-7. Flight information display system at cell phone lot at Salt Lake City International Airport. devices. Unauthorized commercial vehicles (e.g., those without airport permits or AVI tags) cannot gain access to these areas. As noted in subsequent paragraphs, commercial curbside requirements. The extent of the reduced demand is vehicles may be required to abide by other airport regula- a function of the proportion of motorists attracted to park- tions limiting their use of curbside roadway areas. ing who would not have otherwise parked. To encourage the Develop cell phone lot. A cell phone lot (also referred to as use of short-term parking, some airport operators offer free a park and call lot) is a free parking area located away from parking for up to 30 minutes. However, analyses of before- the terminal where a motorist picking up a deplaning pas- and-after data at Seattle-Tacoma International Airport indi- senger can wait until the passenger has gotten off the plane, cate that 30 minutes of free parking had a negligible effect on claimed baggage, arrived at the curbside, and called the curbside requirements. motorist to indicate their arrival at the curb. Cell phone lots Encourage the use of public transit. As described in the enable motorists to use curbside areas efficiently because previous section on Potential Airport Policies to Enhance (1) the airline passengers can tell the drivers exactly where Roadway Operations, by encouraging airline passengers to they are (or will be) located at the curb, (2) if the curbside use public transit, airport operators can reduce airport road- area is congested, the passenger and motorist can arrange an way and curbside traffic. Numerous methods are available alternate pickup location (e.g., a different curbside area), to encourage the use of public transit, including allocating and (3) the motorist will avoid being forced to leave the ter- preferential curb space to publicly or privately operated minal area and possibly recirculate multiple times (e.g., if the public transit services. airline passenger was not ready when the motorist first arrived at the curbside). The operators of some airports (e.g., those serving Phoenix and Salt Lake City) have placed out- door flight information display monitors or dynamic signs presenting this information within cell phone lots to assist waiting drivers (see Figure 6-7). At other airports (e.g., Tampa International Airport), such signs have been installed on the deplaning level curbside to aid waiting motorists and encourage them to exit the curbside when flights are delayed (see Figure 6-8). Several airport opera- tors have or are developing on-airport convenience stores or retail centers where the parking area can be used as a cell phone lot (e.g., Denver International Airport). Provide attractive or free short-term parking. Motorists can be encouraged to park in a conveniently located short- term parking lot if they are confident that they can easily find an empty, reasonably priced space. Encouraging motorists to park while accompanying an airline passenger to/from Figure 6-8. Flight information display system at the terminal rather than using the curbside areas reduces deplaning curbside at Tampa International Airport.

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68 Reduce the Speed of Curbside Roadway Traffic Modifying the amount of space allocated. The amount of space allocated to each category of ground transportation Measures to encourage motorists on curbside roadways to service (including private vehicles) can be increased or operate safely or to slow down and watch for pedestrians cross- decreased to respond to changes in airline passenger activity ing the roadway include the following (in addition to those or curbside requirements, introduction of new transporta- described above under roadway operations): tion services, or new airport policies. Moving assigned spaces. The assigned space can be relo- Use speed humps and speed platforms or tables. These cated to a better (or worse) location near a major exit door devices are forms of raised roadway pavements placed across serving a major airline or to an inner curbside from an outer a travel lane to force motorists to slow down. These devices curbside. are generally used on roadways operating at less than 25 mph. Combining or separating spaces. The curb space allo- The key differences between these devices are their length cated to different categories of ground transportation can be and the amount of speed reduction achieved. Speed humps merged or separated. For example, all courtesy vehicles can are 6 to 12 inches high, and about 4 to 6 feet long with a be required to use a common curbside area rather than sep- gradual sloping approach. Speed platforms or tables are flat-topped speed humps that are long enough for an entire arate space being allocated for the courtesy vehicles serving vehicle to rest on top, and that can function as raised hotels, parking lots, and rental car companies (or these ser- pedestrian crosswalks. Speed platforms can reduce traf- vices can be separated). Requiring single-stop operations. Improved utilization of fic speeds, help indicate the locations of crosswalks to motorists, and minimize grade changes for disabled pedes- available curb space can result from requiring commercial trians crossing the curbside roadway. It is necessary to con- vehicle operators to drop off and pick up passengers at the firm that adequate vertical clearance will be possible prior to same location (e.g., having courtesy vehicles drop off and installing a speed hump or platform on the lower level(s) of pick up their customers on the upper level). This require- a multilevel roadway. The use of speed bumps--raised ment reduces the number of stops and amount of spaces devices 2 feet long or shorter with abrupt slopes--is strongly required by these vehicles. Requiring commercial vehicles or discouraged. public transit to drop off and pick up customers at a single Roadway width restrictions. Narrower lanes or physical location also reduces customer service by requiring more constraints on roadway widths can encourage motorists to level changes and longer walks. drive slowly. Curbside roadway widths can be constrained Using off-peak areas. Improved utilization of existing curb by reducing the number of roadway lanes, or lane widths at space can result from requiring commercial vehicle opera- crosswalks, the ends of median islands, and other locations. tors to drop off and pick up passengers at underutilized areas of the terminal building. An example would be requir- ing commercial vehicles to drop off customers at the bag- Improve Curbside Enforcement gage claim area during the enplaning peak hour or to pick Police enforcement procedures commonly used elsewhere up passengers at the ticketing area during the deplaning can be used to enforce curbside traffic operations at airports. peak hour. Enforcement of dwell times and unattended vehicle prohibi- tions typically receive more attention than speeding on curbside Modify Commercial Ground Transportation roadways. Some airport operators contract with a tow truck Vehicle Operations operator parked at, or near, the curbside entrance to discourage motorists from leaving their vehicles unattended, remaining at Airport operators can establish ground transportation the curbsides too long, or engaging in other improper behavior. rules and regulations that govern how, where, and when a Some airport operators employ traffic control officers ground transportation vehicle operator is allowed to use air- (TCOs) rather than licensed law enforcement officers (LEOs) port roadways. The following section provides additional for curbside operations because of their effectiveness (TCOs information. can focus entirely on traffic control and are not dispatched to other assignments) and cost (TCO wages are typically lower Potential Airport Policies to Improve than those of LEOs); thus, an airport operator can hire more Curbside Operations TCOs than LEOs. Airport operators can require commercial vehicle opera- tors picking up airline passengers to abide by airport rules Revise Curbside Allocation and regulations governing (1) the roadways each operator The space allocated for individual categories of ground may use, (2) where commercial vehicle operators are allowed transportation services can be revised by to stop on the airport roadways to drop off or pick up passen-

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69 gers, (3) the maximum dwell times permitted, (4) the speed side area in excess of a specified maximum dwell time, exceed limits and other restrictions they must obey, and (5) the fees a daily or monthly limit on the number of courtesy vehicle they must pay to operate on the airport. Examples of these trips, and violate established minimum time intervals policies and regulations are provided below. between successive courtesy vehicles they control. Airport Airport operators may require the operators of commer- operators may use these fees to improve curbside traffic oper- cial ground transportation services to pay a variety of fees to ations, discourage unnecessary trips--including those made recover costs or manage demand. These fees include those by an operator seeking to advertise its product or service charged on an annual or monthly basis per company or per (i.e., operating moving billboards rather than transporting vehicle, and cost-recovery fees typically calculated based on customers)--reduce vehicle emissions and improve air qual- the ground transportation operator's volume of vehicle trips ity by encouraging the use of alternative fuel vehicles or con- or volume of airport-related business. Demand management solidated shuttle vehicles through the use of discounted fees, fees include fees penalizing operators that remain in the curb- or achieve other objectives of the airport operator.