The document summarizes a presentation by Kevin Webb on using accessibility analysis and transport modeling to transform transportation. Some key points made in the presentation include that models should be used to explain dynamics rather than just predict outcomes, illuminate uncertainties, demonstrate tradeoffs, and challenge theories. Webb also discusses using models to bound outcomes within plausible ranges and illuminate complex relationships. Specific examples discussed include using models to analyze the impacts of "worst case" and "best case" scenarios and exploring the dynamics of a transit routing app and open source transportation modeling projects.

1. www.TransformingTransportation.org
Taking the Middle Path:
Accessibility Analysis & Transport
Modeling
Kevin Webb, Principal, Conveyal
Presented at Transforming Transportation 2015

2. Taking the Middle Path:
Accessibility Analysis
& Transport Modeling
Kevin Webb

9. Sixteen Reasons Other Than Prediction
to Build Models
1. Explain (very distinct from predict)
2. Guide data collection
3. Illuminate core dynamics
4. Suggest dynamical analogies
5. Discover new questions
6. Promote a scientific habit of mind
7. Bound (bracket) outcomes to plausible ranges
8. Illuminate core uncertainties.
9. Offer crisis options in near-real time
10. Demonstrate tradeoffs / suggest efficiencies
11. Challenge the robustness of prevailing theory through perturbations
12. Expose prevailing wisdom as incompatible with available data
13. Train practitioners
14. Discipline the policy dialogue
15. Educate the general public
16. Reveal the apparently simple (complex) to be complex (simple)

10. 3. Illuminate core dynamics?

12. Worst Case Best Case

16. The Transit App

21. Open Source In Action…