MBTA Green Line 3-Car Train Operating Plans to Enhance Capacity and Reliability Alexandra A ...

149 Pages·2012·11.08 MB·English

MBTA Green Line 3-Car Train Operating Plans to Enhance
Capacity and Reliability
by
Alexandra A. Malikova
Bachelor of Science in Engineering, Systems Science and Engineering
University of Pennsylvania, 2010
Submitted to the Department of Civil and Environmental Engineering
in partial fulfillment of the requirements for the degree of
Master of Science in Transportation
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
June 2012
(cid:13)c Massachusetts Institute of Technology 2012. All rights reserved.
Author............................................................................
Department of Civil and Environmental Engineering
May 21, 2012
Certified by........................................................................
Frederick Salvucci
Senior Lecturer and Research Associate of Civil and Environmental Engineering
Thesis Supervisor
Certified by........................................................................
John P. Attanucci
Research Associate of Civil and Environmental Engineering
Thesis Supervisor
Accepted by.......................................................................
Heidi M. Nepf
Chair, Departmental Committee for Graduate Students

MBTA Green Line 3-Car Train Operating Plans to Enhance Capacity
and Reliability
by
Alexandra A. Malikova
Submitted to the Department of Civil and Environmental Engineering
on May 21, 2012, in partial fulfillment of the
requirements for the degree of
Master of Science in Transportation
Abstract
Transit agencies face a variety of challenges, from increasing ridership to changes in infras-
tructure, to system expansions, all of which require significant preparation to accommodate
the changes without affecting passengers or the agency negatively. The MBTA Green Line,
a Boston light rail system serving nearly 230,000 average weekday passengers, will be un-
dergoing major changes in the next two decades, including nearly doubling of ridership and
system expansion. In order to prepare for these changes, measures need to be taken to
increase capacity and plan for operations on the new segment.
Starting in Fall 2010, the MBTA added to a 2-car train operation, and subsequently
increased, a number of 3-car trains on three of the four Green Line branches, in order
to begin to address the capacity issue. This thesis analyzes service performance before
and after implementation of 3-car trains to find that although scheduled capacity increased
slightly,theactualcapacityofthesystemremainedconstantduringthemorningpeakperiod
and decreased during the evening peak period. Furthermore, there were some negative
impacts with respect to passenger waiting time and running times, thus worsening the
overall passenger experience. However, since 3-car trains will be required for increasing
capacity on the Green Line, it is recommended that trials of 3-car trains continue, with the
restriction that only 2- or 3-car trains operate on a branch. Furthermore, field observations
at terminal stations on two of the branches show differences in operations management
practices, which help explain some variability in service along the route, and point to
strategies to improve service reliability.
Thesis Supervisor: Frederick Salvucci
Title: Senior Lecturer and Research Associate of Civil and Environmental Engineering
Thesis Supervisor: John P. Attanucci
Title: Research Associate of Civil and Environmental Engineering

Acknowledgments
Thank you to Nigel Wilson, John Attanucci, Fred Salvucci, and Haris Koutsopoulos for all
of your help, guidance, editing, input, and countless hours of work. This thesis would not
have been possible without you.
Ginny, you’ve helped me more than you know. Thank you.
TothefolkswhowereonceorstillareattheMBTA—JohnRoderick,DanWebber,Greg
Strangeways, Melissa Dullea, Dave Barker, Brian Dwyer, Ted Timmons, Allison Sweeney,
Bill McClellan, Frank Feltes, Charles Rooney, Peter Brekalis, Pat Kineavy, Tim Hazelton—
thank you for helping me get data, for answering my incessant questions, explaining the in-
nerworkingsoftheGreenLine, andbeingsupportivethroughoutthethesiswritingprocess.
Dom and Jamie—thank you for braving the cold at Riverside. The coffee and pastry
were surely not enough to compensate for your help in the field.
Thank you to my friends in the MST program. It has been a pleasure getting to know
all of you these past two years. In particular, Kevin, you’ve more than helped me keep a
straight head on, through your humor and reassuring words; Micka¨el, merci beaucoup for
your brilliance, company in the lab when the going got tough, and ingenuity with battling
LaTeX; and Gabriel, thanks for helped me fix the “t” so I could finish my thesis about the
T, and your ever insightful academic advice.
Max, thanks for being the role model for me to follow. Bob, you’ve taught me to
persevere regardless of obstacles. And last but certainly not least, Mom, I would not be
where I am today without your guidance, support, and delicious home cooking. Thank you!
5
6
Contents
1 Introduction 17
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.2 Green Line Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.3 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.4 Research Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.5 Thesis Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2 Literature Review 25
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.2 Rail Transit Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.2.1 Signaling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.2.2 Dwell Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.2.3 Turnbacks and Junctions . . . . . . . . . . . . . . . . . . . . . . . . 29
2.2.4 Power System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.2.5 Traffic Signal Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.2.6 Passenger Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3 Real Time Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3.1 Dwell Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.3.2 Traffic Signal Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3 MBTA Green Line 37
3.1 Green Line System Description . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.2 Automatic Vehicle Identification . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3 Operations Control Center and Real Time Control . . . . . . . . . . . . . . 42
7
3.4 Schedule Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.5 Current Green Line Problems . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4 Analysis of Three-Car Train Trials 51
4.1 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.1.1 Reference Time Assignment for AVI Data . . . . . . . . . . . . . . . 54
4.1.2 Data Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
4.1.3 Throughput Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.1.4 Running and Cycle Times . . . . . . . . . . . . . . . . . . . . . . . . 55
4.1.5 Running Time Statistical Analyses . . . . . . . . . . . . . . . . . . . 56
4.1.6 Headways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.1.7 Field Observation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.2 Results of 3-Car Train Analyses . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.2.1 Baseline - Fall 2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.2.2 Trial Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.3 Conclusions from the 3-Car Train Trials . . . . . . . . . . . . . . . . . . . . 100
5 Green Line Operating Scenarios 103
5.1 New Operating Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.2 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
5.2.1 Fleet Constraint Scenarios . . . . . . . . . . . . . . . . . . . . . . . . 107
5.2.2 Additional Service Scenario 2 on D Branch . . . . . . . . . . . . . . 109
5.2.3 PartialFleetConstraintScenario4withAdditionalServiceonEBranch110
5.2.4 Passenger Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
5.3 Results of Scenario Analyses. . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.3.1 Scenario 1: D Branch, Fleet Constraint . . . . . . . . . . . . . . . . 112
5.3.2 Scenario 2: D Branch, Additional Service . . . . . . . . . . . . . . . 112
5.3.3 Scenario 3: E Branch, Fleet Constraint . . . . . . . . . . . . . . . . 115
5.3.4 Scenario 4: E Branch, Partial Fleet Constraint with Additional Service115
5.3.5 Passenger Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
5.3.6 Implications of Scenarios . . . . . . . . . . . . . . . . . . . . . . . . 118
5.4 Operations Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
8
5.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6 Conclusions 125
6.1 Research Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
6.2 Research Findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
6.2.1 Throughput Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . 126
6.2.2 Running and Cycle Times . . . . . . . . . . . . . . . . . . . . . . . . 127
6.2.3 Headway Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
6.2.4 Field Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
6.2.5 Scenario Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
6.2.6 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
6.3 Future Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
A Headway Distributions on B, C, D, and E Branches 133
9
10