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[ Key
Features ]
[ Preprocessing and Data Input
]
[ Powerful graphic representation of schedule
elements ]
[ Advanced
Graphic Display ]
[ Interactive
GUI ]
[ Shifting Trip's Departure Time
]
[ Inserting DH Trips
]
[ Running the automatic features
]
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PT-Manager®
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The PT-Manager® software offers comprehensive
solutions for transit planning focusing on vehicle
scheduling.
Its complex and heuristic algorithms for
fleet-size monitoring/reduction were developed in
reliance on Prof. Ceder's methods which are
described in details in his publications. In
addition, PT-Manger® provides a unique GUI
concept that supports complex schedules while
taking into consideration many constraints and
practical experiences.
The basic flow of using PT-Manger 1.0 contains
three main stages as described below:
- Preprocessing: where all the necessary data
is been prepared and all the required setting
and constraints has been configured.
- Processing: where both custom,
manual, and auto
planning functions are available
- Post processing: where the optimized
schedule can be reported in details
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Figure 1 - PT-Main Screen
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Key
Features
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- Representing schedules by deficit
functions.
- Monitoring complex schedules.
- Detecting challenge points.
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Considering a wild range of practical constraints.
- Working with flexible workspace for manual
optimization.
- Running heuristic algorithms
for optimization.
- Constructing vehicle
chains.
- Report generator.
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Preprocessing and Data Input
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Trips, deadheading trips, and terminals
information
- Handling Trips, Import, add, Edit
- Handling Terminals, Import, add, Edit
- Handling DH (deadheading) trips.
Traffic information
- Handling traffic congestion templates,
Import, add, Edit
- Average deadhead time matrix between each
trip's end and start locations (by
time-of-day)
General Constraints and Configurations
- Maximum Chains' length
- DH operation coast allowed for chain
- Trip recovery-time tolerances (maximum and
minimum waiting-time allowed for next trip
preparation)
- Trip departure-time tolerances (maximum time
deviation allowed for departures)
- Handling pullouts (Average deadheading trip
time; from the minute the bus leaves the
garage locations until it arrives to the
location where the trip starts)
- Handling pull-ins (Average deadheading trip
time; from the minute the trip ends until the
bus reaches its garage locations)
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Powerful graphic representation of schedule
elements
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Trips' graphic representation
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Figure 2 represents a group of trips {T41(b,
a),T42(b, a), T43(b, c), T44(c, c), T45(c, c),
T46(c, b), T47(a, b) sorted by time of day.
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Figure 2 -Trips Group
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Terminals deficit's graphic
representation
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A deficit function (DF) is a step function
defined over the schedule horizon which increases
by one unit with each trip departure and decreases
by one unit with each trip arrival. The DF
represents the number of vehicles required at a
particular terminal. (see figure 3)
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Figure 3 - Deficit Function Of Terminal
d
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Schedule fleet size
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Figure 4 shows how a schedule can be represented by its
terminals' deficit function (fleet size).
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Figure 4 -Schedule fleet size
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Vehicle Schedules
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Figure 5 shows how each line
represents a vehicle schedule
Constructing Vehicle Schedules
(Chains/Blocks) using automatic methods such as
FIFO and the WITHIN Hollow methods. (see
running the automatic features)
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Figure 5 -Schedule fleet size
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Advanced
Graphic Display
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The PT Manager GUI (Graphical User Interface)
concept is designed to display a large amount of
graphical objects such as terminals' deficit
function, trips, and chains.
Users are free to customize their workspace
layout by choosing from the various display
options available. Such options include "one
terminal", "three terminals",
"trips and chains only", "one
terminal and related trips", and much more.
Each deficit function will be displayed in a
single window, and trips and chains will be
displayed by groups. Any schedule change will be
reflected in these windows.
This powerful and friendly GUI concept makes the
PT-Manager a simple and efficient tool for
handling and optimizing transportation schedules.
Figure 6 manifests the difficulty
in handling complex schedules as well as the
hardship in controlling and monitoring the
terminals' difficult functions.
The most unique display features of PT-Manager
is the advanced display of complex schedules
feature. The idea behind the advanced display is
to enable users to focus on and give higher
priority to the problematic deficits. To do so,
the advanced display shows the problematic
deficits only, i.e. those containing challenge
points and all related trips (see figure 7).
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Figure 6 - Complex schedule, standard
representation
Figure 7 - monitoring complex schedule by
deficit threshold
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Interactive
GUI
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By clicking on a particular trip from the
interactive trips window, we may shift its
departure time simply by using the key board
arrows. Those changes will be simultaneously
reflected in the deficit windows.
The advanced display
feature enables users to:
- Arrange workspace
layout and resize the windows to achieve and focus
on what T.E. is concerned with, such as challenge
points.
- Select a trip by clicking on it
inside the graphic trip display.
- Access
trip properties dialogue by double-clicking on a
particular trip.
- Shift a selected trip
using the keyboard arrows.
- Select deficit
pairs for DH trip insertion.
- Insert DH
trips by stretching a line between two deficits
- Click on a deficit and access the relevant
trips.
- Move the level threshold up/down by
using the mouse.
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Shifting Trip's
Departure Time
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Notice the level line in red (Figure 8). It is
set at 4, which means that the user is not
interested in dealing with terminals whose
deficit-max is less than four. Such feature is
very helpful for monitoring a huge number of
terminals. Moving the cursor to the deficit-max
area makes the color of the involved trips black
highlighting the problematic trips.
Figure 8 shows that terminal (d)'s deficit is
six vehicles. We can easily recognize this
challenge point (peak) by eye.
Figure 8 (Highlighting the involved trips)
Now we can simply shift the selected trip
departure time and see how the deficit dialog will
graphically respond to this shift
By looking at the above Interactive DF window,
challenge point (peek=6 vehicles) can be easily recognized.
Once
recognized, the transportation engineer can edit the trips triggering
the challenge point in order to reduce the number
of vehicles required at that particular terminal
(see figure 9, after shifting trip no. 32 ).
Figure 9 (Shifting trips departure time)
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Inserting DH Trip
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Inserting a DH trip from terminal "a" to
terminal "b" will affect the deficit of
both terminals as well as the fleet size. It's
very important for users to evaluate any change in
schedule before actually executing the DH
insertion.
That's why the DH dialog is designed to show
three rows: 1) The deficit of terminal
"a"; 2) The deficit of terminal
"b"; and 3) The fleet size. Figure 8
shows how the DH insertion dialog will immediately
respond to any data insertions even before
accepting them, allowing the user to amend or
cancel such changes if they are not desired (See Figure
10).
Figure 10 - Deadheading trip insertion
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Running the automatic features
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All we need to do in the automatic processing is
to select the appropriate item from the main menu
and simply wait to the final results. At any time
if users are not completely satisfy with automatic
results, he will still be able to make manual
changes.
- Calculate
shift tolerance using automatic methods such as
headway factor.
- Running the SDT (Shift
Departure Time) algorithm Auto DH insert
- Running the auto deadheading trip
insertion algorithm
- Running the SDT and DH
trips algorithm
- Auto chain constructor. Constructs Vehicle Schedules
(Chains/Blocks) using automatic methods such as
FIFO and the WITHIN HOLLOW methods
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