D. DeLaurentis

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School of Aeronautics & Astronautics

Stated Preference Analysis of Stated Preference Analysis of a On-Demand Air Servicea On-Demand Air Service

Employing Very Light Jets Employing Very Light Jets

JTRP Road SchoolJTRP Road SchoolNEXTRANS SessionNEXTRANS Session

March 25, 2008March 25, 2008

Dr. Dan DeLaurentisDr. Dan DeLaurentisAssistant Professor

School of Aeronautics & Astronautics and System-of Systems Signature Area

Purdue Universityddelaure@purdue.edu

765-494-0694

D. DeLaurentis

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School of Aeronautics & Astronautics

The Big Picture: Towards a Robust, Scalable Transportation System Concept

Summary• NASA-funded concept study• High-level, integrated transportation concept (not an aircraft!), representing a view

towards a “New NAS”• Behavior + technologies + disruptions

Goals: Scalability in . . 1. Throughput & accessibility 2. Robustness & natural adaptation

Goals: Scalability in . . 1. Throughput & accessibility 2. Robustness & natural adaptation

Concept Description• A System-of-systems, generated using Network

Theory and Agent-based Modeling to “evolve” new NAS, measure goals, and uncover rules of behavior & network patterns that lead to scalable NAS

Concept Use• Broadly guide technology investment and architecture

for NextGen Air Transportation System • Means to understand & continually reassess the

constituent complex networks, especially unded non-equilibrium conds.

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School of Aeronautics & Astronautics

Networks in the real NAS*

• Transport network– Nodes: aircraft & ATC

– Links: communication

• Capacity network– Nodes: airports

– Links: service routes

• Crew network– Nodes: cities/airports

– Links: crew missions

• Mobility network– Nodes: trip

origins/destinations

– Links: PAX trips

* Terminology courtesy of Bruce Holmes

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School of Aeronautics & Astronautics

“On-demand Air Service” (ODAS)

• In contrast to scheduled commercial air service, ODAS is envisioned to be available “on-demand”, point-to-point, and more accessible via use of local airports.

• The viability of ODAS hinges on three developments: – new aircraft technology, – new business models, and – operational and management policies that allow optimal use of

existing and new infrastructure resources.

Deriving insights on this third element represents the primary motivation for our study

A. Hahn, “Next Generation NASA GA Advanced Concept,” SAE General Aviation Technology Conference and Exhibition, Wichita, KS, 29–31 August 2006, SAE 2006-01-2430.

Eclipse Aviation, accessed 25 January 2007 from www.eclipseaviation.com

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School of Aeronautics & Astronautics

Study Objectives• To build traveler behavior models that predict the

probability of individuals switching from the usual preferred mode of intercity transportation to the new ODAS under a range of plausible scenarios in terms of travel distance and cost.

• The study conducts an econometric analysis of mode choice to understand the likely preferences of individuals in the ODAS context.

• As the ODAS is not yet available, there is a lack of widespread familiarity with it; thus, a stated preference (SP) survey of travelers is conducted to develop the models.

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School of Aeronautics & Astronautics

The Traveler Agent

View of the Survey Instrument

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School of Aeronautics & Astronautics

Survey Conduct

• The Stated Preference (SP) survey was executed through an on-site questionnaire to elicit the traveler attitudes to a new ODAS for intercity travel.

• 372 Samples; representative cross-section of population

• The choice set for the individual consists of the current preferred mode and the new ODAS mode.

• Analysis allows us to understand the respondent preferences to a range of plausible values.

D. DeLaurentis

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School of Aeronautics & AstronauticsTwo Sets of Switching Models

Developed• Single combination switching models

– Dependent variable: whether to switch (or not) to the ODAS from the current preferred mode.

– Explanatory variables: socioeconomic variables and variables related to the new ODAS (e.g. its location).

• Trip purpose switching models– six switching decisions for personal trips are used to

construct a single personal trips switching model – six switching decisions for personal trips are used to

construct a single personal trips switching model– Cost is now explanatory variable

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School of Aeronautics & Astronautics

Sample Results Personal trips

0

10

20

30

40

50

60

70

80

50 - 100 ($) 100 - 200 ($) 200 - 300 ($) 50 - 100 ($) 100 - 200 ($) 200 - 300 ($)

0 - 480 (km) 0 - 480 (km) 0 - 480 (km) 480 - 960 (km) 480 - 960 (km) 480 - 960 (km)

Fare and distance

% W

illi

ng to

sw

itch

Willingness –to-switch data

Model Prediction results

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School of Aeronautics & Astronautics

Findings and Implications (1)• Travel distance, service fare, and the ODAS access location are key

factors influencing user switching decisions.

• The doorstep-to-doorstep travel time savings under ODAS increase with distance, making it a more attractive mode for moderate-distance intercity trips.

• In terms of service fare, while there is a clear preference for the ODAS in several scenarios, the fare ranges need to be carefully determined by operators to achieve the desired market share.

• It appears that the price point differentiator has not been reached

with employed fare ranges; this provides useful insight to operators and aircraft manufacturers on target fare and cost ranges of future VLJ designs.

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School of Aeronautics & Astronautics

Findings and Implications (2)• ODAS location is a key determinant of its operational

viability, and has significant implications for policy-makers, regional planners, operators, and businesses.

• The resulting new air traffic network patterns have fundamental implications for the evolution of the air traffic control systems under NGATS.

• Also, there may be consequent needs in terms of updating the infrastructure in the vicinity of local airports to increase accessibility to the ODAS service and ensure robust performance of the associated surface transportation system.