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OCR for page 22
22 Ground Access to Major Airports by Public Transportation Three Categories of Trip-End Density For the purpose of this research project, three basic categories of trip-end density have been created: Less than 5 airport trip ends per square mile Between 5 and 50 airport trip ends per square mile More than 50 airport trip ends per square mile Each of the three categories has its own challenges. As will be discussed in Step 4, the empiri- cal data suggest that providing services from door to door at trip-end densities of less than 5 trip ends per square mile is extremely difficult and may result in shared-ride services producing basi- cally low-occupancy taxi services under a different name. The examination of geographic areas composed of zones with at least 50 airport trip ends per square mile provides a point of departure for further analysis concerning possible markets for traditional fixed-route and -schedule service. The existence of geographic areas with more than 50 trip ends per square mile is necessary but not sufficient to support these services. Having defined the geographic area of more than 50 trip ends per square mile, the analyst can further explore the characteristics of density within this geographic area, which vary considerably among U.S. airports. Table 1-2 ranks 10 of the 27 most transit-oriented U.S. airports in order of the portion of their ground transportation markets originating in zones with densities greater than 50 trip ends per square mile. Airports Ranked by Orientation to Areas of High Trip-End Density Fixed-route and -schedule service requires a certain density of trip ends to operate at reason- able headways. Table 1-2 shows that, of U.S. airports, only San Francisco International Airport and Reagan Washington National Airport have a majority of trip origins coming from the dens- est category, those areas with more than 50 trip ends per square mile. The use of the category "more than 50 trip ends per square mile" is a surrogate to describe the market areas most susceptible to higher occupancy public mode solutions. It is a first step in the process of identifying specific service proposals, ranging from scheduled hotel loop service (appro- priate to most large airports) to full-scale regional rail transit coverage (applicable to a small number of airports), such as Washington Metropolitan Area Transit Authority (WMATA). Whereas the first data column of Table 1-2 summarizes the extent to which an airport is ori- ented to the highest category of trip density, the second column provides more information about the trip-end density within that geographic area. This information is needed to assess the ability of the market to support fixed-route and -schedule services and can be used as an indica- tor of the potential for high-capacity service to be successful. By far the airports with the great- est concentration of trip ends are in New York with more than 400 trip ends per square mile for this analysis area. At the other extreme, the low trip-end densities for analysis areas in Los Angeles are particularly cautionary in the context of markets to support fixed-route and -schedule services throughout the defined area. Density and Market Support Associated with Specific Modes Next, the analyst should review the existing data concerning the trip-end densities that are sup- portive of various forms of airport ground access services. Looking at the existing services and market support conditions, what do we know about the correlation between trip-end density and specific modal service? What mode shares can be expected within specifically targeted geographic areas? While many factors contribute, clearly volume (and density) of trip ends are critical ele- ments in understanding the ability of specific markets to support specific modal services.

OCR for page 22
Six Steps in a Market-Based Strategy for Improving Airport Ground Access 23 Table 1-2. U.S. airports ranked by orientation to dense urban market. Percentage of airport ground origins from Trip-end density zones with more from these zones, than 50 trip ends per as trip ends per Daily air travelers Airport square mile square mile from these zones San Francisco 57% 225 18,000 Reagan National 52% 216 9,840 New York LaGuardia 49% 409 11,700 New York JFK 44% 310 10,450 Boston 35% 210 9,300 Los Angeles 33% 77 12,970 Washington Dulles 30% 110 4,280 Denver 29% 100 8,600 Seattle 28% 126 4,700 Tampa 25% 126 3,025 SOURCE: TCRP Report 83, MarketSense. A key conclusion of TCRP Report 62 (16) and TCRP Report 83 (47) is that the overall mode share for an entire airport does not reveal the extent to which a given strategy may or may not be working; it does not provide the basis on which to analyze the performance of specific services. Rather, each candidate service needs to be examined in terms of a catchment area in which the serv- ice is a logical choice for the traveler. Using this market research technique, Chapter 6 reviews a set of specific services in the Washington, D.C., area in the context of their logical catchment area. Air Traveler Markets Supportive of Rail Services TCRP Report 83 calculated that the primary geographic market for rail services for air travelers to Boston's airport is characterized by a density of 150 total airport trip ends per square mile. Within this logical catchment area, the Massachusetts Bay Transportation Authority (MBTA) rail services attain a mode share of 16% of the air travelers to Boston's airport. The same analysis process has determined that the prime geographic market for rail services to Reagan Washington National Airport is characterized by a density of 125 total airport trip ends per square mile. Within this logical catchment area, WMATA rail services attain a mode share of 13% of air travelers to Reagan Washington National Airport. Air Traveler Markets Supportive of Regional Collection Points Primary geographic markets were calculated for airport express bus services from regional col- lection points serving airports in Boston, San Francisco, and Los Angeles. Support for these dedicated airport bus services was found in geographic market areas with less than 5 trip ends per square mile. The Van Nuys FlyAway bus service to Los Angeles International Airport was supported by a market area with 8 trip ends per square mile. Express bus services from regional collection points to Boston's airport attained more than 20% mode share in their markets, while the Marin Airporter (San Francisco) captured more than 30% of its primary market area. Similar strong markets are reported from other data sources for longer distance bus and van services serving New York John F. Kennedy (JFK) and Boston airports. Air Traveler Markets Supportive of Door-to-Door Services In both Seattle and Oakland, the logical catchment areas for door-to-door van services were char- acterized by airport trip-end densities averaging about 15 trip ends per square mile. A market area