Urban Transport Modeling (based on these two sources)
description
Transcript of Urban Transport Modeling (based on these two sources)
![Page 1: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/1.jpg)
Urban Transport Modeling(based on these two sources)
A Transportation Modeling Primer
May, 1995
Edward A. BeimbornCenter for Urban Transportation StudiesUniversity of Wisconsin-Milwaukee
http://www.uwm.edu/Dept/CUTS/primer.htm
Modelling Transport: Theory and PracticeFrank McCabe, Dublin Transportation Office
http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html
![Page 2: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/2.jpg)
What’s in the Black Box?
Beimborn, Edward A. 1995. A Transportation Modeling Primer.Center for UrbanTransportation Studies, University of Wisconsin-Milwaukee: http://www.uwm.edu/Dept/CUTS/primer.htm (last accessed 11/14/04).
![Page 3: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/3.jpg)
Travel Demand Modeling
First developed in the late 1950s
Helps make decision on future development of (urban) transport systems
Forecasts travel patterns 15-25 years ahead
Model is predictive, but used prescriptively
A clear understanding of the modeling process and assumptions is essential to understanding transportation plans.
![Page 4: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/4.jpg)
Beimborn, Edward A. 1995. A Transportation Modeling Primer.Center for UrbanTransportation Studies, University of Wisconsin-Milwaukee: http://www.uwm.edu/Dept/CUTS/primer.htm (last accessed 11/14/04).
![Page 5: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/5.jpg)
Limitations of Urban Transport Modeling
Only considers factors and alternatives explicitly included in the equations.If models are not sensitive to certain factors, they will not show any effect of them.This could lead to a conclusion that the factors are ineffective.E.g., bicycle or pedestrianIt is therefore critical to consider the assumptions before decisions are made.
![Page 6: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/6.jpg)
Define problem
Define goals and criteria
Collect data
Forecasting (modeling)
Develop alternatives
Evaluate
Finalize an implementation plan
How do models fit in the transport planning process?
![Page 7: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/7.jpg)
How is Travel Modeled?1. What will our community look like in
the future? How many people? (population forecasts) What will they do? (economic forecasts) Where will they do it? (land use pattern)
2. What are the travel patterns in the future? How many trips? (trip generation) Where will the trips go? (trip distribution) What modes will they use? (mode split) What routes will they take? (traffic assignment) What will be the effects of this travel? (impact analysis)
Beimborn, Edward A. 1995. A Transportation Modeling Primer.Center for UrbanTransportation Studies, University of Wisconsin-Milwaukee: http://www.uwm.edu/Dept/CUTS/primer.htm (last accessed 11/14/04).
![Page 8: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/8.jpg)
Population Forecasts
Birth rates
Death rates
Migration rates
Ages
Often use forecasts from other agencies
![Page 9: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/9.jpg)
Economic Forecasts
Employment levelsForecasted in conjunction with population Basic employmentEconomic multipliers used to estimate nonbasic employmentOften use forecasts from other agencies
![Page 10: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/10.jpg)
Land Use Forecasts
Allocate population and economic growth
1. Establish land use goals and land use rates
2. Allocate to specific locations—models can be used to predict nonbasic and residential from basic
![Page 11: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/11.jpg)
Land Use Forecasting:Limitations
No feedback with transportation plans
Current development is fixed – considers only vacant land
Mixed-use benefits not considered
![Page 12: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/12.jpg)
Existing Land Use of Metro Manila (1996)
![Page 13: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/13.jpg)
Study Area
The area within which trip patterns will be significantly affected by the implementation of transport proposals.
![Page 14: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/14.jpg)
Aggregate Modeling
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 15: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/15.jpg)
Zoning System of Greater Metro Manila
![Page 16: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/16.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 17: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/17.jpg)
Using EMME for the UTP of Iloilo City: An Example
Node
Link
CPU
SM City
from/to Guimaras
from/to South
from/to Airport
![Page 18: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/18.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 19: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/19.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 20: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/20.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 21: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/21.jpg)
Trip Generation Example: Iloilo City
![Page 22: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/22.jpg)
Trip Generation
Done separately for each trip purpose
Two main methods:Multiple regressionCross-classification (a.k.a. category
analysis)
![Page 23: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/23.jpg)
Trip Generation byMultiple Regression, e.g.:
Home-to-work trips (R = 0.99)Oi = -43.6 + 0.097 Population + .773 Employed
Residents - 351 Number of Households + .504 Num Cars Trips to shopping (R = 0.95)Oi = -17.9 + 1.19 Area Res. Land + .266 Number of
Cars Light Commercial Vehicle Trips:Oi = 75.9 + .367Number HHs + .267 Total Empl -.339
Office Empl - .0188 Industrial Empl
![Page 24: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/24.jpg)
Trip Generation byCross-Classification
![Page 25: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/25.jpg)
Advantages Disadvantages
Multiple Regression
1. Familiar methodology2. Statistical significance3. Estimates effect holding other variables constant
1. Assumes linearity2. Aggregate data (ecological fallacy)3. Coefficients not stable over time, or after improvements4. Multicollinearity
Category Analysis
1. Individual data good for predicting individual behavior. 2. Interaction effects 3. Doesn’t assume linearity
1. Needs individual data2. Hard to resurvey individuals for more variables3. Best with naturally discrete variables.
![Page 26: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/26.jpg)
Common Limitation of Trip Generation Models
Independent decisions
Limited trip purposes
Limited independent variables
Trip-chaining is ignored
Lacks feedback with trip distribution, modal split, traffic assignment
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 27: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/27.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 28: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/28.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 29: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/29.jpg)
O-D Matrix (12 zones, Iloilo City)
![Page 30: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/30.jpg)
Trips Attracted (from other zones ) to (Zone 12 – CPU and adjacent areas)
![Page 31: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/31.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 32: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/32.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 33: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/33.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 34: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/34.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 35: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/35.jpg)
Common Limitations of Trip Distribution Models
Constant trip lengths (in minutes) into the futureUse of car travel times in gravity model denominatorIgnores socio-cultural-economic factors for O-D pairsLacking feedback with trip generation, modal split, network congestion
![Page 36: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/36.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 37: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/37.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 38: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/38.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 39: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/39.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 40: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/40.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 41: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/41.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 42: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/42.jpg)
Common Limitations of Modal Split Models
Mode choice affected only by time and cost characteristics
Omitted factors (amenities, crime, safety, security) have no effect
No consideration of ease of walking and comfort of waiting for transit
![Page 43: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/43.jpg)
Modal Split Ignores Pedestrian Friendliness
Beimborn, Edward A. 1995. A Transportation Modeling Primer.Center for UrbanTransportation Studies, University of Wisconsin-Milwaukee: http://www.uwm.edu/Dept/CUTS/primer.htm (last accessed 11/14/04).
![Page 44: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/44.jpg)
Traffic Assignmentalso known as
Network assignment
Route assignment
Network loading
Trip assignment
![Page 45: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/45.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 46: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/46.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 47: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/47.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 48: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/48.jpg)
Wardrop Equilibrium"Under equilibrium conditions, traffic arranges itself in congested networks in such a way that no individual trip maker can reduce his path costs by switching routes".
All used routes between any Origin / Destination pair have equal and minimum costs, while all unused routes have greater or equal costs."
![Page 49: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/49.jpg)
Algorithms
A mechanistic iterative procedure with a:
Starting rule
Iteration rule
Stopping rule
![Page 50: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/50.jpg)
Wardrop Equilibrium Algorithm
Starting rule: set all arc flows to 0, compute all arc costs from cost-flow curve.
Iteration (for each O-D pair):Use shortest path algorithm to find the cheapest route for
each O-D pairShift a fraction of the flow from the old route(s) to the
new cheapest route.Recalculate the new arc flows and arc costs.
Check for convergence:
high-cost route – low cost route < (i.e., tolerance)
![Page 51: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/51.jpg)
Common Limitations of Traffic Assignment Models
Intersection delay is ignoredTravel only on simplified networkIntrazonal travel ignored (affects pollution estimates)Capacities are simplified as a function of number of lanes and type of roadModel ignores time of day. Peak-hour adjustment factor is critical.Peak spreading is not considered.
![Page 52: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/52.jpg)
Final Outputs from Traffic Assignment
Amount of travel, congestion, speed per link
Total transport cost, time, VMT
By applying other coefficients:AccidentsAir pollution
![Page 53: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/53.jpg)
Improving UTMSBetter data
Biking and walking
Auto occupancy
Time of day factors
More trip purposes
Transit-friendly and bike/walk-friendly design
Land use feedback
Intersection delays
![Page 54: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/54.jpg)
Other Critiques to UTMS
Ignores non-transport impacts (energy, neighborhoods, etc.)
Sequential 4-step model doesn’t always match transport decision-making process.
Ecological fallacy (of aggregate data)
![Page 55: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/55.jpg)
McCabe, Frank. Modelling Transport: Theory and Practice. Dublin Transportation Office: http://www.icetact.tcd.ie/icetact/news/transport/mccabe.html (last accessed 11/14/04).
![Page 56: Urban Transport Modeling (based on these two sources)](https://reader031.fdocuments.us/reader031/viewer/2022013004/56813ab7550346895da2b9d8/html5/thumbnails/56.jpg)
Disaggregate Methods
Parcel-based microsimulation
Household Activity Travel Simulation (HATS)