1

REAL-TIME INTER-MODAL SUBSTITUTION (RTIMS) AS AN AIRPORT

CONGESTION MANAGEMENT STRATEGY

Mark HansenYu Zhang

University of California Berkeley

2

Outline

• Diagnosis– Concentration of Delays– Capacity Profiles

• Cure– CDM– Inter-modal substitution– Ground-transport-enabled diversion– Public policy role

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Concentration of Delays

• Spatially

• Causally

• Temporally

• Passenger Impact

4

OPSNET Delay at SFO OAK SJC

0

20000

40000

60000

80000

100000

120000

140000

160000

Nov-01 May-02 Dec-02 J un-03 J an-04 Aug-04 Feb-05 Sep-05 Mar-06 Oct-06

Fl i ght Mi nutes

OAKSFOSJ C

0

1

2

3

4

5

6

7

8

Nov-01 May-02 Dec-02 Jun-03 Jan-04 Aug-04 Feb-05 Sep-05 Mar-06 Oct-06

Percentage ofOperations Delayed

OAK

SFO

SJC

5

Delays at SFO

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Jul-98 Dec-99 Apr-01 Sep-02 Jan-04 May-05 Oct-06 Feb-08

Month

% D

ela

ys

Du

e t

o W

ea

the

r

0%

2%

4%

6%

8%

10%

12%

% O

ps

De

lay

ed

Pct Due to Weather

Pct Ops Delayed

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Concentration of Delays in Time, 2007 to Date

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Pct of Days

Pct

of

Del

ays

>80% of delays on worst 20% of days

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Delay Projections

0

20

40

60

80

100

120

140

160

180

Jan-

01

Jan-

15

Jan-

29

Feb-1

2

Feb-2

6

Mar

-11

Mar

-25

Apr-0

8

Apr-2

2

May

-06

May

-20

Jun-

03

Jun-

17

Jul-0

1

Jul-1

5

Jul-2

9

Aug-1

2

Aug-2

6

Sep-0

9

Sep-2

3

Oct

-07

Oct

-21

Nov-0

4

Nov-1

8

Avg

. To

tal D

elay

(m

in)

2004 Actual

2014 Projection

2025 Projection

Delays projected using JPDO feasible schedulesAssumes weather in 2014 and 2025 the same as 2004

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Statistics—Yearly Delayed Passenger

No. Airport Delayed Passenger

1 LaGuardia 61,120

2 Chicago O’Hare 57,545

3 Newark 37,132

4 Atlanta 28,229

5 San Francisco 24,478

6 Boston 24,120

7 Philadelphia 21,521

8 Dallas Fort-Worth 20,638

9 Los Angeles 17,141

10 Phoenix 14,024

From Evans and Clarke 2002 pp82

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Introduction — Delay in NAS

• Disrupted passengers are only three percent of the total passengers, they suffered 39 percent of the total passenger delay.

From Barnhart et al. 2004

Passenger Average Delay % Passengers% Total

passenger Delay

Disrupted 303 minutes 3.20% 39%

Non-disrupted

16 minutes 96.80% 61%

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Historical Capacity Scenarios at SFO

0

2

4

6

8

10

12

14

16

Time of Day

Quarter-Hourly AAR

61681635925

11

Historical Capacity Scenarios at OAK

0

2

4

6

8

10

12

14

AAR7

1

AAR7

3

AAR8

1

AAR8

3

AAR9

1

AAR9

3

AAR1

01

AAR1

03

AAR1

11

AAR1

13

AAR1

21

AAR1

23

AAR1

31

AAR1

33

AAR1

41

AAR1

43

AAR1

51

AAR1

53

AAR1

61

AAR1

63

AAR1

71

AAR1

73

AAR1

81

AAR1

83

AAR1

91

AAR1

93

AAR2

01

AAR2

03

AAR2

11

AAR2

13

AAR2

21

AAR2

23

AAR2

31

AAR2

33

Ti me of Day

Quarter-Hourl y AAR

59410179732

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Clustering of Joint Clusters at SFO and OAK

0

5

10

15

20

25

30

AAR7

1

AAR7

3

AAR8

1

AAR8

3

AAR9

1

AAR9

3

AAR1

01

AAR1

03

AAR1

11

AAR1

13

AAR1

21

AAR1

23

AAR1

31

AAR1

33

AAR1

41

AAR1

43

AAR1

51

AAR1

53

AAR1

61

AAR1

63

AAR1

71

AAR1

73

AAR1

81

AAR1

83

AAR1

91

AAR1

93

AAR2

01

AAR2

03

AAR2

11

AAR2

13

AAR2

21

AAR2

23

AAR2

31

AAR2

33

Ti me of Day

Quarter- Hourl y AAR

45. 70%1. 40%31. 30%21. 60%

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Air Traffic Flow Management (ATM)

• Ground Delay Programs (GDP)– Ration-by-Schedule (RBS) – Compression

• Collaborative Decision Making (CDM)– Flight Schedule Monitor (FSM) – Ration-by-Schedule (RBS)– Compression– Slot Credit Substitution (SCS)

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Procedure of Collaborative Decision Making (CDM)

ATCSCC, Facilities and AOCs Evaluate Demand vs. Ca

pacity

Proposed GDP Advisory

Is the GDP still required?

End

AOC Response(Cancellations)

No

YesIssue GDP

(RBS)

AOC Response(Re-ordering and

Cancellations)Compression

Exit loop whenprogram expiresor is cancelled

AOC SmartCancellation Problem

Slot Credit Substitution

Based on Metron 2004

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Ideas

Substitute short-haul flights with surface transport when capacity temporarily drops at hub airports

Divert flights to alternate airports and provide surface transport between alternate and original airports.

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Hub-and-Spoke Network

Bottleneck: hub airport with capacity constraints

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Inter-modal Substitution of Short-haul Flights

Fast link

Slow link

bt

wta

bt Transport time on slow link

wta Transport time on fast link and delay due to node capacity

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Inter-model Substitution plus Diversion

Fast link

Slow link

bt

wta

bt Transport time on slow link

wta Transport time on fast link and delay due to node capacity

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Why Focus on Short-haul Flights?

• Provide airlines more flexibility to make smart tactical cancellations– More capacity for large-jet operations – allow cancellation decisions to be made with more

reliable capacity information.

• Reduce miss connections and passenger delay– Canceling short-haul flights inconveniences fewer

customers– Passengers save time if the extra transportation

time with surface modes is less than the flight delay they would encounter.

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Numerical Example ― Input

Airport: San Francisco International Airport (SFO)

Schedule: a typical Thursday in 2004

Source: the Official Airline Guide (OAG)

Airline: a hypothetical feeder airline (Airline S) serving all segments less than 5

00 miles. Detail:

130 flights from 6:00am to 12:00am (18 hours). Capacity:

severe capacity shortfall starting from 6:00am and ending at 10:00am.

two arrivals per hour in the shortfall period and eight arrivals per hour afterwards.

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Scheduled and Hypothetical Cumulative Arrivals without Cancellation

0

20

40

60

80

100

120

140

6 8 10 12 14 16 18 20 22 24 26

Time of day

Cumulative numberof arrivals

Scheduled ArrivalHypothetical Arrival

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Numerical Example ― Programming and Solution

w/ocancel

Cancelw/ IMS

Total cost ($) 1720888 731003

Cancellation 25

Substitution 22

See more results

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Combined Concept

Inter-modal substitution

Diversion

Operate as usual

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Public Policy Role

• Individual airlines unlikely to implement these ideas on their own

• Policy interventions– Push airlines to reduce operations in periods or

reduced capacity (pricing)– Assist airlines in developing systems for

surface transport to enable real-time substitution and diversion