Cervenka NCTCOG IOWA PeerReview

Information about Cervenka NCTCOG IOWA PeerReview

Published on February 29, 2008

Author: Francisco

Source: authorstream.com

Content

Travel Demand Modeling At NCTCOG:  Travel Demand Modeling At NCTCOG Presentation For IOWA TMIP Peer Review March 30 – April 1, 2004 Slide3:  ﴀ ﴀ Slide4:  Total Population Within The Dallas – Fort Worth Metropolitan Planning Area Four-Step TRANSCAD Modeling Process:  Four-Step TRANSCAD Modeling Process TRIP GENERATION TRIP DISTRIBUTION MODE CHOICE ROADWAY ASSIGNMENT TRAVEL TIME CONVERGENCE TRANSIT ASSIGNMENT NO YES ZONE LAYER DEMOGRAPHIC INFORMATION ROADWAY NETWORK TRANSIT NETWORK LOOP ROADWAY SKIMS TRANSIT SKIMS INPUT PROCESS DECISION Transition To Reality:  Transition To Reality Actual Scope Of Human Behavior  Model Scope All Person Trips  Motorized Person Trips All Travel Purposes  HBW, HNW, NHB, And Truck Purpose Categories All Occupations  Basic, Retail, And Service Jobs All Households  Income And Household Size Categories (Plus Auto Ownership Breakdowns) All Streets  Non-Local Streets Individual Data  Aggregate Data (Zones) Slide16:  AUTOMATED NETWORK CONVERSION Roadway Preparation:  Roadway Preparation Link Free Speed (Based On Speed Limit, Distance, Area Type, Functional Class, And Intersection Control) Directional Hourly Capacity (Based On Lanes, Area Type, Functional Class, And Divided/Undivided Designation) Time Period Capacity AM Peak, PM Peak, And OffPeak Trip Generation:  Trip Generation GISDK Macro Language Seven “Regular” Internal-Internal Trip Purposes 4 HBW, 1 HNW, 1 NHB, And 1 Truck Inputs Population, Households, Income, And Basic/Retail/Service Jobs Special Generators (Shopping Malls, Colleges, Hospitals, Airports) Household Income Distribution:  Household Income Distribution Total = 1 0.11 0.13 0.19 0.57 Household Size Distribution:  Household Size Distribution Demographics For Special Generators:  Demographics For Special Generators Current Special Generators Regional Shopping Malls With Over 500,000 Square Feet (20) Colleges/Universities With Over 1,500 Enrolled Students (27) Hospitals With Over 300 Service Employees (42) DFW And Love Field Airport Terminals (Special Treatment) Special Input Data Fields (e.g., For Shopping Malls) SGRETAIL = Number of Jobs In Zone That Relate To The Shopping Mall SGUNIT = Total Leasable Square Footage (Thousands Of Square Feet) HBW, HNW, NHB, And Truck Trip Rates Per Thousand Square Feet External Station Trip Tables:  External Station Trip Tables Internal-External And External-Internal (IE/EI) Weekday Passenger Vehicles (Total Trip Ends) External-External (EE) Weekday Passenger Vehicles IE/EI Weekday Trucks (Six Or More Tires) EE Weekday Trucks (Six Or More Tires) Mode Choice Inputs:  Mode Choice Inputs Auto Travel Roadway Travel Time Roadway Length (Operating Cost) Daily Parking Cost Transit Travel In-Vehicle Transit Travel Time (Includes Dwell) Walk (Or Drive) Access Time Walk Transfer And Egress Time Initial And Transfer Wait Time Transit Fare Market Segment And Area Type Constants Market Segmentation:  Market Segmentation Objective: To Account For Differences In Commuter Behavior Segmentation Basis (6 HBW And 6 HNW) Household Income (3) Low Medium High Vehicle Availability For A Household (2) Vehicles Less Than Persons Vehicles Greater Than Or Equal To Persons HBW Mode Choice: Mainframe vs. TRANSCAD:  HBW Mode Choice: Mainframe vs. TRANSCAD Choice Drive Alone Shared Ride 3+ Shared Ride 2 Transit Drive Transit Walk Choice Drive Alone Shared Ride 3+ Shared Ride 2 Transit Drive Transit Walk Auto HNW Mode Choice: Mainframe vs. TRANSCAD:  HNW Mode Choice: Mainframe vs. TRANSCAD Choice Drive Alone Shared Ride 2+ Transit Drive Transit Walk Choice Shared Ride 3+ Shared Ride 2 Transit Drive Transit Walk Shared Ride Drive Alone Transit Drive NHB Mode Choice: Mainframe vs. TRANSCAD:  NHB Mode Choice: Mainframe vs. TRANSCAD Choice Drive Alone Shared Ride 2+ Transit Drive Transit Walk Choice Drive Alone Shared Ride 3+ Shared Ride 2 Transit Drive Transit Walk Transit Assignment:  Transit Assignment Four Multi-Path (Pathfinder) Production-Attraction Assignments For All HBW Transit Trips Peak Transit-Initial Drive Access (Park-and-Ride) Peak Transit-Initial Walk Access (No Park-and-Ride) For All HNW And NHB Transit Trips Offpeak Transit-Initial Drive Access (Park-and-Ride) Offpeak Transit-Initial Walk Access (No Park-and-Ride) Traffic Assignment Preparation:  Traffic Assignment Preparation PA To OD Trip Table Transposing, Time-Of-Day Factoring, And Aggregation Of Trip Purposes AM Peak Period (2.5 Hours) PM Peak Period (3.5 Hours) Off Peak Period (18 Hours) K Factoring Of OD Trip Tables (Post Mode Choice) Compensate For Gravity Model Limitations OD Estimation Procedure To Help With Problem Identification Adjustments/Checks Based On Screenline Results Traffic Assignment:  Traffic Assignment User Equilibrium Generalized Cost (Three 30-Iteration Assignments) A.M. Peak (6:30a – 8:59a: 2.5 hours) P.M. Peak (3:00p – 6:29p: 3.5 hours) OffPeak (18 hours) Four Vehicle Classes Loaded Simultaneously Drive Alone Shared-Ride “Sees” HOV Lanes Shared-Ride “Doesn’t See” HOV Lanes Trucks (Vehicles With 6 Or More Tires) Speed vs. V/C Ratio (Example):  Speed vs. V/C Ratio (Example) Traffic Model Limitations:  Traffic Model Limitations Ideally, the peak and offpeak congested speeds directly from traffic assignment should be used in trip distribution—but we “post process” because the assignment-calibrated parameters do not give us realistic speeds Related to above: “Peak Spreading” is not directly considered; in the future, we may consider peak hour and “shoulder of the peak” assignments We have no observed data to directly calibrate HOV-Toll usage; instead, we have to rely on our separately-calibrated HOV modeling and “toll road value of time” modeling Traffic Model Limitations (Cont.):  Traffic Model Limitations (Cont.) The Offpeak assignment represents 18 hours of the day—perhaps a future breakdown into Mid-Day Offpeak (9:00 a.m. – 2:59 p.m.) and Evening/Night Offpeak (6:30 p.m. to 6:29 a.m.) All passenger vehicles are assumed to have the same value of time Calibration/Validation Issues (Transit):  Calibration/Validation Issues (Transit) Reasonableness Of Peak and Offpeak Transit Speeds Used In Skimming For Mode Choice (Observed And Future) Coded vs. Observed Bus And Train VMT Modeled vs. Observed Weekday Riders By Bus Route And Rail Route (Route-Level RMSE And Percent Error) Modeled vs. Observed Weekday Rail Station Boardings (Station-Level RMSE And Percent Error) Reasonableness Of Modeled vs. Observed Mode Of Access Distributions To Individual Rail Stations Calibration/Validation Issues (Traffic--Slide 1):  Calibration/Validation Issues (Traffic--Slide 1) Current And Future-Year Reasonableness Of Roadway Speeds Used In Skimming For Trip Distribution And Mode Choice Reasonableness Of Modeled vs. Observed Percent Intrazonal Trips By Trip Purpose (DFW = 1.5% For HBW; 8.7% For HNW; 9.3% For NHB; And 0.5% For Trucks) Reasonableness Of Modeled vs. Observed Average Person Trip Lengths (Or Trip Length Frequency Distributions) By Trip Purpose, For Interzonal Trips Modeled vs. Observed Weekday Link Volumes By Functional Class (RMSE And Percent Error) Calibration/Validation Issues (Traffic—Slide 2):  Calibration/Validation Issues (Traffic—Slide 2) Modeled vs. Observed Weekday Screenline Volumes (Overall Magnitude And % Error); DFW = 1262 Links On 89 Screenlines Modeled vs. Observed AM Peak, PM Peak, And OffPeak Auto And Truck VMT By Functional Class (% Error) Check Very High And Very Low AM, PM, And OffPeak V/C Ratios Checks Of The “Hundred Largest Link Errors” Report Magnitude And % Error Calibration/Validation Issues (Traffic—Slide 3):  Calibration/Validation Issues (Traffic—Slide 3) “True” Validation Requires Calibration Sensitivity Tests AND Forecast Sensitivity (Or Sensibility?) Tests Calibrated Model “Backcast” Checks Would Be Nice, Although Historical Model Validity Is Still No Guarantee Of Forecastability Individual Capacity-Per-Lane Changes To Improve Validation? No, But Consider More Functional Classes Keep In Mind The Prime Objectives For Modeling Link-Specific Changes Are Problematic For New Links Calibration/Validation Issues (Traffic—Slide 4):  Calibration/Validation Issues (Traffic—Slide 4) Individual Link Speed/Impedance Changes To Improve Validation? No, But Check Speed Limits And Functional Class Check Reasonableness Of Free And Congested Speeds Try To Find The Underlying Cause Change Centroid Connectors To Improve Validation? Sure (But Apply Modifications In Some Logical Manner) Don’t Forget “Forecastability” Of The Connectors Caution On Zone Sizes Factor Trip Tables To Improve Screenline Validation Results? Yes—But Exercise Due Caution On Forecastability Not Theoretically Elegant! Check First For Trip Generation Problems Recommendations For Model Applications Work At NCTCOG:  Recommendations For Model Applications Work At NCTCOG Every Modeling Study Needs “Direct Oversight” By A TransCAD Model Applications Champion -- So, What Is A Champion? Is Very “Hands-On” Experienced With TransCAD We Can Test People On This, Too! Has A Good Understanding Of GIS And Travel Model Theory Maybe We Should Give An Oral Certification Test! …And (Ideally) Spends Over 70% Of His/Her Time On Model Applications Work

Related presentations


Other presentations created by Francisco

Finding Nemo
07. 11. 2007
0 views

Finding Nemo

Yeopresentation 000
13. 04. 2008
0 views

Yeopresentation 000

forKoreaLA
27. 03. 2008
0 views

forKoreaLA

AGE OF IMPERIALISM
14. 03. 2008
0 views

AGE OF IMPERIALISM

S1 Respdrugs
05. 03. 2008
0 views

S1 Respdrugs

Green Eggs And Ham correct
27. 02. 2008
0 views

Green Eggs And Ham correct

daddy day camp
20. 02. 2008
0 views

daddy day camp

SIFT Forth
07. 01. 2008
0 views

SIFT Forth

The Sonnet
02. 10. 2007
0 views

The Sonnet

lecture3spr07
04. 10. 2007
0 views

lecture3spr07

Explosives
08. 11. 2007
0 views

Explosives

cex kr t4
01. 12. 2007
0 views

cex kr t4

Conjoint Analysis
02. 11. 2007
0 views

Conjoint Analysis

Chapter 02 Engineering Ethics
05. 11. 2007
0 views

Chapter 02 Engineering Ethics

Los Pronombres Reflexivos
05. 11. 2007
0 views

Los Pronombres Reflexivos

2003MonsterCalendar
06. 11. 2007
0 views

2003MonsterCalendar

Motions of the Celestial Sphere
13. 11. 2007
0 views

Motions of the Celestial Sphere

Ames Internship 2004 10
15. 11. 2007
0 views

Ames Internship 2004 10

Measuring Customer Satisfaction
16. 11. 2007
0 views

Measuring Customer Satisfaction

SemTag and Seeker
20. 11. 2007
0 views

SemTag and Seeker

Chapter8Overview
21. 11. 2007
0 views

Chapter8Overview

Evaluation of Student Learning
13. 12. 2007
0 views

Evaluation of Student Learning

Virtual Public Diplomacy
23. 12. 2007
0 views

Virtual Public Diplomacy

generational cohorts
27. 12. 2007
0 views

generational cohorts

Chapter 20
28. 12. 2007
0 views

Chapter 20

Introductory Lecture1
06. 12. 2007
0 views

Introductory Lecture1

ln ltc EDCD
01. 01. 2008
0 views

ln ltc EDCD

water harvesting in antiquity
02. 01. 2008
0 views

water harvesting in antiquity

Solar Eclipse Through Sp4
04. 01. 2008
0 views

Solar Eclipse Through Sp4

Bienvenidos a la Clase
17. 12. 2007
0 views

Bienvenidos a la Clase

section2
23. 11. 2007
0 views

section2

3176 2630
29. 11. 2007
0 views

3176 2630

cattaneo01
26. 11. 2007
0 views

cattaneo01

UGAmain2
28. 09. 2007
0 views

UGAmain2

telepharmacy presentation 42503
23. 11. 2007
0 views

telepharmacy presentation 42503

JMcKane Restrict
02. 11. 2007
0 views

JMcKane Restrict

xuan part1
07. 01. 2008
0 views

xuan part1

GIPP 2007
27. 09. 2007
0 views

GIPP 2007

casestudy angsana
10. 12. 2007
0 views

casestudy angsana

Anthology
01. 11. 2007
0 views

Anthology