A Transparent and Economically Efficient Process for Determining Planned Airport Capacities
-
Upload
rogan-humphrey -
Category
Documents
-
view
26 -
download
3
description
Transcript of A Transparent and Economically Efficient Process for Determining Planned Airport Capacities
CENTER FOR AIR CENTER FOR AIR TRANSPORTATION SYSTEMS TRANSPORTATION SYSTEMS RESEARCHRESEARCH
A Transparent and Economically Efficient Process for Determining
Planned Airport Capacities
Phil Railsback
Center for Air Transportation Systems Research
George Mason University
CACATSRTSR
Why Determine Planned Capacities?
Delays Are a Function of Planned (Scheduled) Airport Capacity
Economic Cost of Reliability to• Passengers• Airlines
Recognizing Property Rights of Slots to Holders• Slots Can Be A Scarce Resource• Codification of Rights Helps Establish Value• Slots Being Claimed as Financial Assets
CACATSRTSR
Choosing a Planned Capacity
“Planned” v. “Scheduled”
Planned Capacity Must IncludeScheduled Operations (Airlines)
Unscheduled (“Pop-Up”) Airline Operations
General Aviation Operations (US Part 135 and 91)
Unscheduled Operations Must be Taken Into Account in Policy and Planning
CACATSRTSR
Definitions
Time PeriodSlots Are Considered Fungible Within a Time Period
Airport StateOpen v. Closed, IMC v VMC, Runways in Use
Planned CapacityPolicy-Established Upper Bound on Operations
Realized CapacityActual Maximum Number of Operations Possible in a
Specific Time Period on Day of Operations
CACATSRTSR
Definitions (continued)
Slot AvailabilityProbability of a Planned Slot Being Realized on Day
and Time of Operations
Slot FailureEvent Where a Planned Slot is Not Realized
Priority ClassSub-grouping of Slots Within a Time Period to
Support Multiple Slot Priorities
CACATSRTSR
Randomness and Capacity
Capacity is a Function of Random Processes• Weather• Inter-Arrival Rate Randomness• Departure-Arrival Interference• Fleet Mix Dependence (Wake Vortex)
Therefore Capacity is a Random Process• Capacity is Properly Described as a Probability
Density Function (PDF)
CACATSRTSR
Airport State Identification
{Closed, IMC, VMC} X {Runway Configurations}e.g.
IMC using 22/13 (Arrival/Departure)VMC using 13/13 etc.
Randomness Leads to a Capacity Distribution by StateCan be Determined by Analysis or Empirical Measurement
Inter-Arrival Randomness, Arrival-Departure Interference, Fleet Mix Variation
Each State Has a Probability of OccurringState Frequencies are Empirically Measurable
CACATSRTSR
Airport Capacity
Airport States Form a Partitioning
Each State Has a Capacity Distribution
Probability of a Realized Capacity (RC) is(by Law of Total Probability)
)_()_()(_
StateAirportRCpStateAirportpRCpStatesAirport
CACATSRTSR
Example: LGA
•State-Specific Capacity PDFs•Based on Historical Data by State•Selected only Time Periods When Operating at Capacity•Shows Very Little Weather Dependence
0
0.05
0.1
0.15
0.2
0.25
Arrivals per 15 Minutes
Prob
abili
ty
vmc_4_4 vmc_4_31 vmc_4_13 vmc_31_31
vmc_31_4 vmc_22_31 vmc_22_22 vmc_22_13
vmc_13_13 vmc_13_4 imc_4_4 imc_4_31
imc_4_13 imc_31_31 imc_31_4 imc_22_31
imc_22_22 imc_22_13 imc_13_13 imc_13_4
CACATSRTSR
Planned Capacity and Slot Availability
There is a Relationship Between Planned Capacity and the Realized Capacity Distribution
The Relationship Results in• Slot Availability (%)• Expected Number of Unplanned Slots
CACATSRTSR
Derivation of Slot Availability
Partition By Possible Realized Capacities
Each Combination of Realized Capacity (RC) and Planned Capacity (PC):• RC >= PC, p is 1• RC < PC, p is RC / PC
Slot Availability:
)()0
,1min()_( RCpRC PC
RCPCnrealizatioslotp
CACATSRTSR
Unplanned Slots
Reducing Planned Capacity Increases System Reliability at Cost of Reduced Utilization
U(PC): Expected Number of Unplanned Slots
e.g.: 9 Planned Slots, 12 Realized Slots• 3 Unplanned Slots – Opportunity Cost
The Expected Value is:
0),0max()()(
RCPCRCRCpPCU
CACATSRTSR
Example: LGA
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 2 4 6 8 10 12 14 16 18 20
Planned Arrivals per 15 Min
Slo
t A
vailab
ilit
y
CACATSRTSR
Example: LGA
0
2
4
6
8
10
0 2 4 6 8 10 12 14 16 18 20
Planned Arrivals per 15 Minutes
Exp
ecte
d N
um
ber
of
Un
pla
nn
ed
Slo
ts
CACATSRTSR
Economic Efficiency
What is the Most Efficient Planned Capacity?• Maintain System Reliability v. Maximize Throughput
We Need Slot Valuation as a Function of Slot Availability
Then Maximize Summed Slot Valuation:• e.g.: 5 Slots at 98% valued at 900 € each• 10 Slots at 85% valued at 400 € each• 4500 € > 4000 € → Plan 5 Slots
CACATSRTSR
Auctions Can Provide Valuation
Auctions Provide Value Discovery Across Multiple Operators
We Can Integrate Desired Availability into a Slot Auction• Auction Availability/Priority Classes, or• Have Bidders Specify Desired Availability in Their
Packages– Might be Prone to Auction Gaming
Necessary Condition for Operators’ Product Differentiation by On-Time Performance
CACATSRTSR
LGA Example: Priority 2 Slots
Compare:
5 Priority 1 Slots, 98% Availability and
(from previous plot)
5 Priority 2 Slots, 71% Availability; or
(from this plot)
10 Priority 1 Slots, 84%(from previous plot)
0
0.2
0.4
0.6
0.8
1
1 3 5 7 9 11 13 15 17 19
Priority 2 Planned Arrivals per 15 Minutes
Prio
rity
2 Sl
ot A
vaila
bilit
y
CACATSRTSR
Conclusions
Provides Simple, Transparent Relationship Between Availability and Planned Capacities
Shows How Market Mechanisms (Auctions) Can Provide Answer to Trading Off Throughput and Reliability
Data Are Critical to Results
Insights Into Airport Behavior