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Technical Advisory Committee
July 2, 2014
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Today’s Agenda Preliminary Demo of GTAModel V4.0
GTAModel V4.0 Component Overview File System Structure GTAModel V4.0 Model System Transit Assignment Calibration Fare specification for FBTA (time permitting)
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Component Overview
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GTAModel V4.0 – Component Outline
Synthetic Population Place of Residence Place of Work Place of Residence Place of School Activity Generation Location Choice Mode Choice Station Access Choice
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Synthetic Population Based on TTS Household records
Aggregated households on to the planning district level Redistributed to each zone randomly closely matching population by zone Requires to be run with access to the TTS Database / Computer Will be replaced in the future with a superior model in the near future (V4.01)
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Place of Residence Place of Work
Four occupations Full-Time / Part-Time 3 worker categories No Car or no License License and less cars than drivers License and at least as many cars as drivers
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Place of Residence Place of School
Updates proportionally by zone the base year’s linkages. School zones are assigned discreetly through a random process If no linkages existed in the base year then another zone from the planning district is used instead. To help increase the fit we assign school zones without replacement
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Activity Generation Activity generation times / rates are generated from TTS data Activities are first broken down by frequency Then they are broken down into start times Finally for each start time it is broken down by duration
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Location Choice Three location choice models
Market Work Based Business Other The models look at the previous and next episodes and only include feasible trips into the choice set according to auto travel time
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Mode Choice - Modes Auto Carpool (Interhousehold passenger / taxi)
Passenger (Intrahousehold passenger) Drive Access Transit (DAT) Walk Access Transit (WAT) Bicycle Walk (all way) Rideshare (joint trip auto) Schoolbus
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Mode Choice - Algorithm
Generate a list of all feasible tours for each non shared mode If a tour uses a tour based mode compute the tour level utility (needed for DAT) Find the best tour using the restrictions of what vehicles they use In our case it is car / no car Assign available resources to people by tour Given the resource assignments we then try to match drivers with passengers if it provides a better household level utility Joint trips then share mode choices with other tour members
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Station Access Choice For DAT discrete choice needs to be made to see what station will be chosen to access the transit network This station will be used for both access and egress Utilities are calculated on a tour based level A station is only chosen once the DAT mode has been selected as the wanted mode after vehicles have been assigned
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File System Structure
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Overview Activity Distributions BaseYearMatrix Documentation
Employment HouseholdData Transit Fares ZoneData
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Model System
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Model System Template -Tasha Runtime
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Main Components Household Loader Network Data Scheduler Modes
Location Choice Model Modes Auto Mode Other Modes Shared Modes Mode Choice Auto Type ( mainly used for future expansions ) Zone System
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Expansion Components Pre Run Pre Iteration Post Scheduler
Post Household Iteration Post Household Post Iteration Post Run
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Used Expansions Pre Run Post Iteration Post Household
Computes Auto and Transit’s initial network data Post Iteration Computes next iteration’s Auto and Transit network data Post Household Builds then stores the demand matrices for Auto and Transit
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Resources Used for storing important pieces of data that are used between multiple modules The EMME Modeller Controller Jobs by occupation and employment status Allow for dynamic loading
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Traffic Assignment
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Traffic Assignment Overview and Parameters
Standard Traffic Assignment Use link-based generalized cost for tolls Light and Regular Fare Zones for the 407ETR Includes transit background traffic Peak Hour Factor (AM/PM) Representative Hour Factor (Midday, Evening) Toll Percption
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TTS Data Extraction For each time period, extracted the matrix conditional on the following: Trips started within the time period Primary mode was D, M, T, or was a drive-access-transit trip For drive-access-transit trips, only trips to valid network stations were included No trips were extracted for overnight (assumed freeflow traffic conditions)
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Cordon Count Data Used 2011 Cordon Count data
Toronto, Durham, York, Peel, and Halton data were included For AM/PM periods, determined the peak hour of traffic volume Compared count post data against the traffic volume for the peak hour
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AM Peak Hour Factor Use a PHF = 0.437
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PM Peak Hour Use a PHF = 0.385
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Midday/Evening Representative Hour
The highest demand within the midday and evening period comes at the shoulders of the AM and PM periods, respectively Therefore no need to represent the peak of demand, just divide by the number of hours in the time period Midday Assignment Period = Evening Assignment Period = 0.2
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Toll Perception
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Screenline Results [Refer to handout]
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Transit Assignment
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Model Overview Congested Transit Assignment (captras.mac port)
Includes ALL transit modes in one assignment GO Rail, GO Bus, and Subway lines all use segment speeds All others use line speeds Assumed no service in the Overnight time period Walk-on-links permitted Logit model on outgoing centroid connectors (Emme 4+ only) Headways based on average arrival interval in the time period Speeds based on scheduled time and route length
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Transit Assignment Parameters
Congestion Perception Fare Perception Wait time Perception Walk Perceptions Toronto Access Toronto Walk-on-network Non-Toronto Egress Non-Toronto Walk-on-network IVTT Perception = 1.0
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Transit Assignment Parameters (cont’d)
Boarding Penalties Subway Brampton TTC Bus Durham YRT GO Bus VIVA GO Train Halton Hamilton Mississauga Streetcar (Regular, XROW)
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Transit Assignment Parameters (cont’d)
Boading Penalty Perception (not estimated) GO Train Headway fraction Consistently estimated to be 0.2 (compared to 0.5 for the rest of the network) Walking speed Assignment Period The only parameter which is different for each time period
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TTS Data Extraction - Demand
Extracting transit demand matrices Assigned to the 4 time periods based on trip start time 5 classes of trip: Walk-acces-egress transit (WAE) Station-access, walk-egress GO (SAG) Station-access, walk-egress Subway (SAS) Walk-access, station-egress GO (SEG) Walk-access, station-egress Subway (SES) Exluded trips which used a transit route not in the network
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TTS Data Extraction - Demand
For SAS/SES: First/last route respectively must be TTC Subway station of access/egress must have a TTC parking lot For SAG/SEG, the first/last route respectively must be GO
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TTS Data Extraction – Calibration Data
For each time period, for each trip class (WAE, SAG, SAS, SEG, SES): Boardings for each transit route Matrix of transfers, including initial boardings and final alightings, for the following groups of transit lines: Brampton Transit MiWay Durham Region Transit TTC Bus GO Bus TTC Streetcar GO Train TTC Subway Oakville, Burlington, Milton Transit York Region Transit VIVA Hamilton Street Railway
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Estimation Procedure Extract TTS demand matrices
Determine time period assignment period For each model: Determine parameters Code tool Estimate parmeter values using XTMF Calibrate parameter values by hand Repeat 3 until satisfied with model results
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Transit Assignment Period
Used to calculate transit line capacity Represents the number of hours for which the demand matrix is applied Inverse of the Peak Hour Factor (which gets applied to the demand matrix for Auto Assignment) A different value is required for each time period
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AM Assignment Period Start End Trip Starts 6:00 6:59 101,045 6:15 7:14
157,558 6:30 7:29 178,371 6:45 7:44 224,476 7:00 7:59 239,287 Peak Hour Factor Assignment Period 7:15 8:14 273,443 0.49 2.04 7:30 8:29 268,165 7:45 8:44 242,053 8:00 8:59 218,245 Total 558,578
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PM Assignment Period Start End Trip Starts 15:00 15:59 173,731 15:15
16:14 187,511 15:30 16:29 182,630 15:45 16:44 195,199 16:00 16:59 199,193 16:15 17:14 229,627 Peak Hour Factor Assignment Period 16:30 17:29 232,947 0.33 3.03 16:45 17:44 218,193 17:00 17:59 212,767 17:15 18:14 159,503 17:30 18:29 150,470 17:45 18:44 123,037 18:00 18:59 119,225 704,915
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Midday, Evening Assignment Periods
The highest demand within the midday and evening period comes at the shoulders of the AM and PM periods, respectively Therefore no need to represent the peak of demand, just use the # of hours in the period Midday Assignment Period = 6.0 Evening Assignment Period = 5.0
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Model 1 Description Congested transit assignment (5 iterations)
Estimated on AM dataset NOT using fare perception (i.e. not fare-based)
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Model 1 Parameter Values
Congestion Penalty Perception 0.41 Wait Time Perception 2.23 Toronto Walk Perception 1.2 Non-Toronto Walk Perception 1.3 Boarding Penalty Perception 0.8 GO Train Headway Fraction 0.2 Walking speed (km/hr) 5 -Access and walk-on-network folded into a single parameter
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Model 1 Parameter Values
Brampton Boarding Penalty 9 Durham Boarding Penalty 2.5 GO Bus Boarding Penalty 15 GO Train Boarding Penalty 7.5 Halton Boarding Penalty 2.75 Hamilton Boarding Penalty 6 MiWay Boarding Penalty 3 Streetcar Boarding Penalty Streetcar XROW Boarding Penalty Subway Boarding Penalty 2.25 TTC Bus Boarding Penalty 2 YRT Boarding Penalty 5 VIVA Boarding Penalty
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Model 1 Results: AM Boardings
Group TTS Model Error % Error Brampton 21,096 17,925 ,170 -15% Durham 10,055 9,172 -9% GO Bus 10,330 16,269 5,939 57% GO Train 98,304 101,130 2,826 3% Halton 6,796 6,105 -10% Hamilton 22,952 19,168 ,784 -16% Mississauga 36,760 41,457 4,697 13% Streetcar 56,887 52,549 ,337 -8% Subway 361,520 356,509 ,011 -1% TTC Bus 318,859 315,096 ,763 VIVA 6,986 7,916 930 YRT 16,119 13,628 ,491 AM TOTAL 966,664 956,925 ,739
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Model 1 Results: AM Transfers
[Please refer to handouts]
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Model 1 Results: PM Boardings
Group TTS Model Error % Error Brampton 27,428 23,603 ,824 -14% Durham 10,522 11,043 520 5% GO Bus 14,048 18,360 4,313 31% GO Train 98,622 113,421 14,799 15% Halton 8,882 8,003 -10% Hamilton 30,131 25,375 ,756 -16% Mississauga 51,447 58,566 7,119 14% Streetcar 77,676 63,440 ,236 -18% Subway 470,499 439,530 ,969 -7% TTC Bus 415,776 397,171 ,605 -4% VIVA 9,934 12,715 2,782 28% YRT 20,190 17,046 ,143 PM TOTAL 1,235,154 1,188,274 ,880
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Model 1 Results: PM Transfers
[Please refer to handouts]
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Model 2 Description Congested transit assignment Using Fare Perception
Still work-in-progress for GTAModel 4.1 Could include transit speed updating
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Fare Based Transit Assignment
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Overview To get around technical limitations of Emme’s transit assignment implementation, a “hyper-network” is required to model transit fares A Python tool has been developed to generate this network This process has been abstracted and generalized to be specified using a single XML file, interpreted by the tool This way, arbitrary fare scenarios can be coded up and designed
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Transit line groups The XML file contains a list of transit line groups Each group is defined by a selector expression (i.e. an expression which is true for all transit lines in the group) Each group becomes a ‘layer’ in the hyper network In other words, transfers between lines in the same group are free In order for the algorithm to be work, each transit line must belong to a group Each transit line belongs to one group only
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Fare Rules Each rule consists of a cost (positive or negative)
Costs can be applied to either links or transit segments LINK rule types: initial boarding, transfer SEGMENT rule types: zone crossing, in-vehicle distance Rules are additive E.g. if a link qualifies for two rules, its assigned cost will be the sum of both rules The procedure checks for negative costs once all rules have been applied
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FBTA Miscellaneous Example Fare Schema File (.xml) for 2012 is available from the TMG Website A report has been written documenting usage and summarizing details (also available on the website) New fare rules could possibly be implemented if requested, as long as they are representable in Emme (e.g. cannot do origin-destination-specific fares)
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Thank you! Any questions?
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