Title: Cube Voyagers Public Transport Module
1Cube VoyagersPublic TransportModule
2PTs Design Overview
- Provides a multi-user-class, multi-routing
transit algorithm which - Represents all the complexities of the public
transport system - Uses efficient techniques to determine what
different traveler's would consider to be
reasonable public transport routes. - Allocates the demand between the various routes
in a way similar to how travelers actually chose
their routes
3Represents Complexity of PT Systems
- The route, where it stops (boarding and
alighting both, only boarding, only alighting),
and its variations (sub-routes) by period of the
day. Details such as boarding delays at selected
stops.. - The type of vehicle providing the service (bus,
light rail, heavy rail, ferryetc.) and its
capacity (seated and crush). (capacity restraint
is provided in PT) - Information about multiple PT operators and their
operating/fare policies - Full representation of circular routes
- Uses function of roadway speed, set travel times
via time points, used fixed time.
4PT Methodology
- Compiles Data and Simplifies Network (Produces
NET file) - Enumerates Acceptable Discrete Routes for every
I-J (RTE file) - Finds least cost route
- Enumerates all other routes within defined limits
- Evaluates Routes and Performs Analysis
- Decisions on access and assignment to individual
lines through a series of logit choice models. - Route evaluation through a hierarchical logit
choice model.
5PT Steps
- Enumeration finds a traveler's reasonable public
transport routes from origin to destination - Identifies full discrete routes
- The route should move progressively from the
origin to the destination - Travelers tend to select journeys that are
simpler that are direct or involve few
interchanges - Travelers are unwilling to walk very long
distances - These principals are used to constrain the
potentially huge computational task of
identifying all reasonable routes - The process can be considered analogous to a
traveler using a map to reject routes which are
very long relative to more direct alternatives - Creates a dataset of the reasonable routes
between each origin and destination by user class
6PT Steps
- Evaluation qualitatively judges the routes
calculated in the route enumeration stage of PT - The elements that can be used in this process
- Limit on the number of transfers
- The difference (actual percentage) difference
between the minimum cost route and the evaluated
route - Limit on non-transit cost (walk/drive access)
- Limit on waiting and transfer times
- Limit on In-vehicle costs
- Specified by user class or market segment
- Provides attractive and reasonable routes along
with their probability of being used and the
costs of each of the routes. - Calculates the probability of using each path
using choice models at each decision point
7Route Choice Probability
Note you can visualize route choice percent
allocations to calibrate model parameters to
known or expected routing patterns (i.e. not
only does the skim make sense but does the
multi-path routing make sense)
8Tools to Build and Maintain a PT Model
- Networks
- PT System Data
- Access Links (Automatic and/or Manual Coding)
- Fare Systems
- Multiple User Classes
- Transfer Rules
- Wait curves
- Crowding
- Skims (Cost Time)
9Building Maintaining PT Networks
- Ability to create and edit PT Lines in Cube
Graphics - Ability to create and edit PT lines in Cube GIS
with PT transit data stored in geodatabase - Ability to open multiple PT line files at once
- AUTOMATIC UPDATES to PT lines to confirm to
Highway Network edits - Tools to copy and reverse PT lines
- Transit Line Manager for easier management
10Transit Line Manager
11PT System Data- Vehicle Characteristics
- Public Transport Fleets are grouped by
- Mode
- Operator
- Vehicle Type
- Vehicles are given perceived time factors to
designate desirableness. - Vehicles are given seated and crush capacities.
- Capacity curves are defined to establish
penalties based on the volume to capacity ratio. - Vehicle travel-times may be obtained from
- Factoring congested roadway speeds
- Speed variables in the network
- Route schedule time-tables
12PT System Data Manager
13Multiple User-Classes
- Each user-class may have unique factors which
determine - Which routes are reasonable
- How much walking?
- How many transfers?
- What are the access characteristics?
- What is the maximum cost?
- What is the maximum travel time?
- Which routes are desirable
- What is the perceived time for walking,
transferring, waiting, riding (by mode)? - Are there rebates or special fare systems?
- What is the sensitivity to crowding/capacity
restraint? - What is the value of time?
- What is the willingness to pay?
14User Class-Specific Factors
- MUMEXTRACOST (search beyond minimum cost)
- MUSTUSEMODE (a single or group)
- REBESTPATHCOST (alternate methods)
- RECOSTMAX (max cost considered)
- REWAITMAX (caps wait times)
- REWAITMIN (insures minimum wait time)
- RUNFACTOR by mode
- SERVICEMODEL (used in evaluation)
- SPREADCONST (multipath enumeration only)
- SPREADFACT (multipath enumeration only)
- SPREADFUNC (multipath enumeration only)
- VALUEOFTIME by mode
- WAITFACTOR by node (safety, amenities, etc)
- XFERCONST (mode to mode penalties)
- XFERFACTOR (mode to mode penalties)
- XFERPEN (can be negative)
- XWAITCURVE by node
- The FACTORS keywords are
- ALPHA (relative weight of walk to rest of
journey) - AONMAXFERS (controls route search with MAXFERS)
- BESTPATHONLY
- BRDPEN by mode
- CHOICECUT (multipath only)
- DELACCESSMODE (deletes access modes from paths)
- DELEGRESSMODE (deletes egress modes from paths)
- DELMODE (any modes out of path building)
- EXTRAXFERS1 (controls route search with MAXFERS)
- EXTRAXFERS2 (controls route search with MAXFERS)
- FARESYSTEM (obvious)
- FREQBYMODE (headways across modes or not)
- IWAITCURVE by node
- LAMBDAA (multipath only)
- LAMBDAW (multipath only)
- MAXFERS (maximum transfer cutoff)
15Fare System Representation
- All sorts of complex fare systems can be modeled
by user class - FREE No cost incurred
- FLAT One fixed cost per use
- DISTANCE Possible boarding cost unit cost per
distance or cost lookup table - FROMTO Fare zone matrix based on the start/end
zones - COUNT Counts number of fare zones crossed, sum
number of zones crossed - ACCUMULATE Each fare zone has a fare and when
crossed adds to cost - HILOW Fare result of the highest and lowest fare
zone number crossed - Simple TAZ-TAZ fare matrices
16Access Link Procedures
- Access and Transfer links can be input via
- Automatic generation through analysis of the
network - External file
- Network attribute
- Automatic generation of non-transit links
- Walk access to the stops, time and distance may
be calculated along the network or using straight
line connections. - Automobile access to the stops are calculated
along the network for kiss-and-ride or
park-and-ride. - Code park-and-ride lots and specify contributing
zones or set maximum travel times or distances. - Wait curves may be specified to calculate wait
time for boarding and transferring. These may be
unique by location, mode, or user-class - Automated process limits increased to 999
access/egress/transfer links can be generated for
any give node for each mode
17Wait Curve Specification
Note you can visualize and implement up to 255
shapes of wait curves that can be applied by node
and further modified by waitfactor by mode
18Crowding Model
- Crowd modeling is an iterative process enabling
the capacity of a Public Transport System to
influence the travel times in the system and thus
the routes found and their probability of use, as
calculated during route evaluation. - Two types of crowding model may be used
- Link travel time adjustment
- Wait time adjustment
19Ways to Implement the Crowding Model
- Link travel time adjustment
- The link travel time adjustment models passenger
perceptions that travel time is more onerous when
they have to stand (rather than sit), or when the
vehicle is crowded. The adjustment is represented
by a crowding factor, which is multiplied by
in-vehicle time to give the perceived value of
crowded in-vehicle time. - Wait time adjustment
- In the context of a transit leg from a boarding
point to an alighting point with several lines
operating, demand (without crowding) is allocated
using the service frequency model (SFM), or
service frequency cost model (SFCM). The wait
time adjustment redistributes the initial SFM or
SFCM loadings whenever any line does not have the
available capacity to take its allocated demand.
This excess demand is reallocated to other lines
which have spare unused capacity, and incurs
additional wait time. - The additional wait time (due to not being able
to take the first service) may make this route
less attractive, and so cause diversion of demand
to other enumerated routes for the
origin-destination pair.
20Skimming the PT Network (SKIMIJ)
- Available Skims
- COMPCOST Skims Composite Costs
- ValOfChoice Skims Value of Choice
- IWAITA/P Skims Initial Wait Times
Actual/Perceived - XWAITA/P Skims Transfer Wait Times
Actual/Perceived - CWDWAITA/P Skims Crowding Wait Times
Actual/Perceived - TIMEA/P(Mode) Skims Travel Time Actual/Perceived
- CWDCOSTP Skims Crowding Link Travel Times
Perceived - BRDPEN(Mode) Skims Boarding Penalty Perceived
- XFERPENA/P(Mode) Skims Transfer Penalty
Actual/Perceived - DIST(Mode) Skims Distance
- BRDINGS(Mode) Skims Number of Boardings
- BESTJRNY Skims Best Journey Times
- FAREA/P(Mode) Skims Actual/Perceived Fares in
Monetary units - EXCESSDEMAND Skims Excess Demand in Crowding
Model - EXCESSPROP Skims Excess Proportion in Crowding
Model
21Report and Visualize PT Results Inputs
- Reports
- Graphics
- Record Processing
22PT Assignment Line Report
Note you can get summaries for totals or by
user-class for up to 10 user classes at a time
sorted by mode, operator or line name
23PT Assignment Graphics
On, Off and Through
Line Profile
24Advanced Analysis Techniques
- Select Link Analysis
- OD Matrix Estimation
25Select Link Analysis
- Allows the user to generate matrices of trips
which satisfy a certain condition. - Optionally the selected trips may be assigned to
the network for further analysis and
visualization. - Selections may be any combination or exclusion
of - Traversed Links and/or Nodes
- Lines
- Modes
- Operators
26Examples of Select Link Queries
- The general form of the select link function is
- SELECTLINK (expression)
- MW1 SELECTLINK(L1023-1027)
- MW3 SELECTLINK(L101-102, 104-105, 107-109)
- MW1 SELECTLINK(LINERED1)
- MW2 SELECTLINK(LINEA, B)
- MW5 SELECTLINK(MODE3,5,7-9)
- MW7 SELECTLINK(OPERATOR3)
- MW2 SELECTLINK((L101-102 LINERED)
(L201-202 LINEBLACK)) - For conditions using node selection (that is, N
conditions) the TYPE keyword can take the
following values - THRU, to consider transit legs passing through
the node - BOARD to consider transit legs boarded at the
node - ALIGHT to consider transit legs alighted from at
the node - NTTHRU to consider nontransit legs passing
through the node - e.g. MW2 SELECTLINK((N123 TYPEALIGHT)
(N123 TYPEBOARD))
27Demand Analysis
- The select process returns the demand for an I-J
pair which satisfies a selection criterion. - The proportion of demand meeting the criterion
may be obtained by including the keyword
PROBABILITYT in the expression. In a similar
manner percentages may be obtained by using the
keyword setting PERCENTT. - e.g. MW3 SELECTLINK(LINETRAM1, PERCENTT)
returns percentage values for each I-J pair which
use the line TRAM1. - The select link process may load the portion of
total demand meeting a select link criterion,
rather than loading the entire demand as
specified by the PARAMETER TRIPSIJ. - This is invoked by including the keyword and
setting LOADT in the select link expression - e.g. MW2 SELECTLINK(L303-307, LOADT)
28OD Matrix Estimation
- Cube Analyst can perform matrix estimation on the
in conjunction with the PT Module. - The process takes as Input
- Initial Matrix
- Partial Matrices
- Trip Ends
- Link Counts
- Line Counts
- Transit Line Ons/Offs/Throughs
- All Input observations are given a level of
confidence. This allows data from different
sources to be properly considered and weighted.