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Analyzing Travel DemandManagement Strategies: the Promise of Activity-       Based Travel Demand Models                   ...
Overview of Questions I Hope to Answer1. What is an “Activity-Based Travel Demand Model”?2. What is it about these activit...
Activity-Based Travel Demand Model?A few principles•   People want to do activities, and they travel in order    to partic...
Activity-Based Travel Demand Model?A few principles•   Household and social structures influence activity    and travel  ...
Activity-Based Travel Demand Model?A few principles •   No cart before the horse / driving home if you     walked to work ...
Activity-Based Travel Demand Model?A few principles•    No cart before the horse driving home if you walked     to work / ...
Activity-Based Travel Demand Model?          A few principles                        Sum of all small behavior types is th...
Activity-Based Travel Demand Model?What it comes down to:• A less-cool-looking version of sim-city.       SAN FRANCISCO CO...
Activity-Based Travel Demand Model?Every Sim has a:• role• income• age• gender• household                                P...
Activity-Based Travel Demand Model?Every Worker Simchooses a workplacebased on:• Job type/income  match• Accessibility to ...
Activity-Based Travel Demand Model?Every Sim Householddecides how many carsthey want:• How easy is it to get to  work with...
Activity-Based Travel Demand Model?Every morning, each Simwakes up and asksthemselves “Gee, whatam I going to do today?”• ...
Activity-Based Travel Demand Model?If they are goingsomewhere other than towork, the Sim will pickwhat the primary reasonf...
Activity-Based Travel Demand Model?Then they need to pickthe primary way that theyare going to get there.• Accessibility b...
Activity-Based Travel Demand Model?If they need to makestops along the way, theypick places that areconvenient to the tour...
Activity-Based Travel Demand Model?Once the entire tour isplanned out, the Simchoses the exact modethat they will use for ...
Activity-Based Travel Demand Model?Based on congestionlevels and otherpreferences, the Sim thennavigates their waythrough ...
Activity-Based Travel Demand Model?All of these choices arecarried out by theindividual with fullknowledge of their:• Othe...
Good for TDM Strategy Analysis?•    Depends on the strategy. Can it be represented in     ABM framework? Can it be just as...
ABM -- Good for TDM Strategy Analysis?Pros• Understands induced and latent demand If you build that HOT lane, more people...
ABM -- Good for TDM Strategy Analysis?Pros• Explicit representation of interdependencies If my child has swim practice, I...
ABM -- Good for TDM Strategy Analysis?Pros• Lots of choices for performance measures Each sim is tracked and can be accou...
ABM -- Good for TDM Strategy Analysis?Pros• Simulation framework is flexible You can “do something else” to your Sim You...
ABM -- Good for TDM Strategy Analysis?Pros• Simulation framework is flexible Our Sims just learned about the benefits of ...
ABM -- Good for TDM Strategy Analysis?Pros• Can easily implement what if scenarios: Can still do sans data. Test a hypoth...
ABM -- Good for TDM Strategy Analysis?- Pros• Understand the system• Recognize unintended consequences Can we build our w...
ABM -- Good for TDM Strategy Analysis?Cons•   Is it overkill ?•   Is it easier to run a pilot and find out vs. spend a few...
Who has these tools?     SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY   28
Thanks for inviting me      to this community to speak!(we are open to suggestions about how to    provide info for better...
“…A major advantage of activity based modeling lies in   its ability to give a better understanding and prediction   of tr...
“…trip based four step aggregate methodology, is  inadequate in analyzing the sustainable transport  policies. ““A review ...
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Analyzing Travel Demand Management Strategies: the Promise of Activity-Based Travel Demand Models

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Presented at the 2013 Transportation Research Board Annual Meeting in Washington DC.

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  • …but I might not answer them in order!
  • Cat Telecommute photo: License Some rights reserved by seandreilingerI’m sure Academics and practitioners alike can argue with this list, but I think these are important for our discussion today.Travel is a derived demand. This is an important consideration especially if we are thinking about serving people’s needs with less of it. However (unrelated), it’s also important to consider that just as there is a concept of a “travel budget” for a day (a ceiling amount of traveling you are willing to do), there is also a psychology concept of a “social interaction floor” – the fact that people who aren’t going to work often partake in many more out of home activities…they go to the grocery store much more frequently, etc.This is an important consideration when devising TDM strategies such as telecommuting. We see it in the data, and we can also actually also show it with an AB model.Telecommuting can mean different things in different places – and that can mean different things for the efficacy of using it as a TDM strategy.Person on the left is being social with his cat…and looking out the window at suburbia – he’ll probably make a few trips (probably driving) out of the house just to interact with real people.People on the right walked down the street to a coffee shop.A good AB model understands that there isn’t just substitution effects for in- and out-of home activity…but that there is latent demand for out of home activity.
  • A lot of models or sketch planning tools tend to aggregate together demographics from what is around you into “you”. AB modeling explicitly recognizes that these sums of people actually exist in a structure…and that structure matters. Households with school-age children behave extremely differently than households without children. A parent that needs to drive their kid to school at a certain time is far less like to flex their time at work to take advantage of off-peak commuting hours…and is also a lot less likely to vanpool/carpool to work. Most newer activity-based models explicitly understand how a kid’s school location and transportation options directly impact their parent’s day-patterns.Even older activity-based models contain variables and understandings of how your household structure affects your choices.
  • 3.
  • Transcript of "Analyzing Travel Demand Management Strategies: the Promise of Activity-Based Travel Demand Models"

    1. 1. Analyzing Travel DemandManagement Strategies: the Promise of Activity- Based Travel Demand Models Elizabeth A. Sall SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY Transportation Research Board Annual Meeting Sunday January 13th, 2013
    2. 2. Overview of Questions I Hope to Answer1. What is an “Activity-Based Travel Demand Model”?2. What is it about these activity models make them better (or not) for analyzing TDM Strategies?3. What does a specific TDM strategy look like in an activity model? (a few examples)4. Who has these activity models anyways? SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 2
    3. 3. Activity-Based Travel Demand Model?A few principles• People want to do activities, and they travel in order to participate in them  travel is a derived demand. SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 3
    4. 4. Activity-Based Travel Demand Model?A few principles• Household and social structures influence activity and travel  there‟s a lot more to „you‟ than the zone around you. Flickr: MNicoleM SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 4
    5. 5. Activity-Based Travel Demand Model?A few principles • No cart before the horse / driving home if you walked to work / leaving work before you got there  interdependence explicitly recognized.If it looks like But you don’tthis outside have a car atevery morning… work now…then you’ll So even ifprobably the evening autodecide to… commute is cake, you’ll need to… SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 5
    6. 6. Activity-Based Travel Demand Model?A few principles• No cart before the horse driving home if you walked to work / leaving work before you got there  interdependence explicitly recognized.If this area where you You realize that ifwork has a congestion you drive like thisfee from 4 to 6 pm… In the AM… That it will cost you like this $ In the PM… And you live here… SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 6
    7. 7. Activity-Based Travel Demand Model? A few principles Sum of all small behavior types is the majority of behavior  we are all unique, and that is important. 0.18 0.16 0.14 Income $0-30kP robability Dens ity Income $30-60k 0.12 Income $60-100k 0.1 Income $100k+ 0.08 0.06 0.04 0.02 0 $- $5 $10 $15 $20 $25 $30 Value of T ime ($/Hour) SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 7
    8. 8. Activity-Based Travel Demand Model?What it comes down to:• A less-cool-looking version of sim-city. SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 8
    9. 9. Activity-Based Travel Demand Model?Every Sim has a:• role• income• age• gender• household Population Synthesis SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 9
    10. 10. Activity-Based Travel Demand Model?Every Worker Simchooses a workplacebased on:• Job type/income match• Accessibility to work Workplace Destination Choice SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 10
    11. 11. Activity-Based Travel Demand Model?Every Sim Householddecides how many carsthey want:• How easy is it to get to work with and without a car?• How easy is it to get to other stuff around the house with and without a car?• Demographics Auto Availability SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 11
    12. 12. Activity-Based Travel Demand Model?Every morning, each Simwakes up and asksthemselves “Gee, whatam I going to do today?”• How easy is it to get to work?• What else do I need to do today?• Demographics Tour Generation SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 12
    13. 13. Activity-Based Travel Demand Model?If they are goingsomewhere other than towork, the Sim will pickwhat the primary reasonfor leaving the house is:• Accessibility• Schedule Tour Destination Choice SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 13
    14. 14. Activity-Based Travel Demand Model?Then they need to pickthe primary way that theyare going to get there.• Accessibility by mode Tour Mode Choice SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 14
    15. 15. Activity-Based Travel Demand Model?If they need to makestops along the way, theypick places that areconvenient to the tourmode that they havechosen to their primarydestination.• How far a detour is it from my main trip?• Near transit transfer point/freeway exit? Intermediate Stop Choice SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 15
    16. 16. Activity-Based Travel Demand Model?Once the entire tour isplanned out, the Simchoses the exact modethat they will use for eachsub-part of theirexcursion from home(aka tour). Trip Mode Choice SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 16
    17. 17. Activity-Based Travel Demand Model?Based on congestionlevels and otherpreferences, the Sim thennavigates their waythrough the network toparticipate in activitiesand carry out their plans. Route Choice SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 17
    18. 18. Activity-Based Travel Demand Model?All of these choices arecarried out by theindividual with fullknowledge of their:• Other choices• Activity needs / Household• Physical / Temporal constraints• Demographics SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 18
    19. 19. Good for TDM Strategy Analysis?• Depends on the strategy. Can it be represented in ABM framework? Can it be just as well represented in 4S model?• Existing Tools? Do you already have an AB model?• Got Data? Does the data already give you the answer to the question that you have?• Risk/Reward? Depends on the questions that you need to have answered and how sure you want to be about them.(And if you can‟t articulate a question that you are trying to answer, there are much morerewarding places to sink time and money) SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 19
    20. 20. ABM -- Good for TDM Strategy Analysis?Pros• Understands induced and latent demand If you build that HOT lane, more people are going to drive. If you make it easier to park, more people are going to drive. Hard to build your way out of congestion. SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 20
    21. 21. ABM -- Good for TDM Strategy Analysis?Pros• Explicit representation of interdependencies If my child has swim practice, I need to drive today. If I need to stay late at work and transit is bad afterrush hour, I will drive. If I bike down a hill, I have to bike back up it. Bike Accessibility To Bike Accessibility From SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 21
    22. 22. ABM -- Good for TDM Strategy Analysis?Pros• Lots of choices for performance measures Each sim is tracked and can be accounted forindividually or across multiple demographic orgeographic dimensions. Future GHG Production per HH sfmobility.org SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 22
    23. 23. ABM -- Good for TDM Strategy Analysis?Pros• Simulation framework is flexible You can “do something else” to your Sim Your Sim can become aware of new information Your Sim‟s decisionmaking can have more/new/better rules or models SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 23
    24. 24. ABM -- Good for TDM Strategy Analysis?Pros• Simulation framework is flexible Our Sims just learned about the benefits of bike lanes Trip Difference - Bike Projects Daily Tours v4.1 Harold v4.3 Fury Bike 500 0.1% 3,000 0.8% Walk 1,100 0.0% -500 -0.0% Transit 850 0.0% -600 -0.0% Auto -2,400 -0.0% -1,300 -0.0% Total 0 0.0% 600 0.0% SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 24
    25. 25. ABM -- Good for TDM Strategy Analysis?Pros• Can easily implement what if scenarios: Can still do sans data. Test a hypothesis! What if we had a compressed work week? We could assume that:  commuting would be 20% less  work duration a few hours longer  only full time workers affected Tested in Burlington:  -4% overall trips  Only slight VMT decrease SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 25
    26. 26. ABM -- Good for TDM Strategy Analysis?- Pros• Understand the system• Recognize unintended consequences Can we build our way out of GHG issues with bike lanes? If our transit system becomes the most popular thing on earth how many people would ride it? SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 26
    27. 27. ABM -- Good for TDM Strategy Analysis?Cons• Is it overkill ?• Is it easier to run a pilot and find out vs. spend a few years and $1 million developing a model ?• Do you really just need a back of the envelope guess?….but once you have it you will find so many questionsthat it is good at answering. SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 27
    28. 28. Who has these tools? SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 28
    29. 29. Thanks for inviting me to this community to speak!(we are open to suggestions about how to provide info for better decisions) elizabeth@sfcta.org www.sfcta.org/modeling SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY
    30. 30. “…A major advantage of activity based modeling lies in its ability to give a better understanding and prediction of traveler responses to TDM measures and other types of transportation policies. ““ These improved estimates of the changes in important transportation variables, then, provide the basis for the development of more accurate estimates of emission reductions that would result from the implementation of one or more TDM strategies.” Shiftan Y. et al “Activity-based Modeling as a Tool for Better Understanding Travel Behaviour” IATBR Conference Paper. Lucern, 10-15 August 2003. SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 30
    31. 31. “…trip based four step aggregate methodology, is inadequate in analyzing the sustainable transport policies. ““A review of … activity based travel demand modeling found that they are capable of handling such policies better than conventional models and are assistive to the decision makers in arriving at right mix of polices specific to the situations. ” Malayath, Manoj and Ashish Verma. “Activity based travel demand models as a tool for evaluating sustainable transportation policies” Research in Transportation Economics Volume 38/Issue 1. Feb 2013. SAN FRANCISCO COUNTY TRANSPORTATION AUTHORITY 31

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