Volvo Summer Workshop Track 2: Urban Transportation Physics

1. Volvo Summer WorkshopTrack 2: Urban Transportation Physics Carlos Daganzo

2. Outline • Focus • Mass motions in cities • How things work? • New technologies • New policies • Projects • BLIPS • Green Logistics • Gridlock • Self synchronizing buses • Evacuation • Safety

3. BLIP Concept • Right lane reserved for bus but open to traffic when bus is not near by, like IBL. • CMS and in-pavement lights dynamically restrict and allow access to lane. • One CMS per block • Rules of the road: Drivers bound by CMS message until next CMS is reached. Eichler and Daganzo, 2005, Bus Lanes with Intermittent Priority: Assessment and Design

4. Complexity Fades Away Results do not rely on particulars of how the “cocoon” is achieved. One example of cocoon formation.

5. Green Logistics – Implemented schemes Geroliminis and Daganzo (2005), A review of green logistics schemes used in cities around the world

6. Water use - Coordinated transport A DHL-boat sails through the canals and serves as base-centre for bicycle-couriers • reduction of 150.000 van-km / year • TOTAL COST: 7,000€ Amsterdam - Floating Distribution Centre

7. Clean vehicles • hybrid (clean and quiet) and energy efficient electric vehicles • urban distribution centre (UDC) • large trucks for long-distance transport to and from the UDC and of vans and small trucks for the centre. combining an efficient goods distribution concept with the environmental impact of electric vehicle transport Rotterdam - ELectric vehicle CIty DIstribution System Total Cost: 1.2 million EURO

8. Conclusions • Promising city logistics schemes with “green” characteristics • Largest and fastest growing cities in the developing world: ABSENT • Schemes can be combined, adapted and modified to be of use (HOW? Research is necessary)

9. Gridlock In Cities Nikolas Geroliminis

10. Self-Stabilizing Bus Routes Josh Pilachowski

11. Statement of Problem • Two parts of travel time • Time to travel between stops • Time to pick up and drop off passengers • Bus routes by their very nature are unstable • Demand is stochastic • Small variation in demand can create large instability over time without control • Queue proportional to headway • Increased demand Slows bus Larger headway Increased demand • Decreased demand Speeds up bus Smaller headway Decreased demand • Buses eventually come together and act as a single unit

12. Sustainability • Attracting Ridership • Minimum ridership needed to derive environmental benefits • Ridership from necessity as opposed to desire • Spare-the-Air days • Inherent Instability • Routes with smaller headways are more unstable • Smaller headways comes from higher use • Equity • Bus vs. Rail

13. Control Methods • Station Control • Holding • Station Skipping • Interstation Control • Speed Control* • Traffic Signal Preemption • Other • Adding/Removing Vehicles • Early Turns

14. Existing Controls • Instability still exists • Not many controls to alleviate this • Establish slack time • Estimate delays on route and add a fixed amount to the expected trip time • Control points • Determine certain stops as control points • If a bus arrives at a control point ahead of schedule it waits there

15. Existing Controls • Expand on the idea of control points • By increasing the number of control points errors have less time to propagate • Control points require slack time built into the schedule • A bus behind schedule cannot make up lost time easily • Passengers don’t like sitting on the side of the road • Station Control  Interstation Control • Continuous control points become speed control

16. Speed Control • Dynamic stabilization • AVL allows buses to continually locate adjacent buses • Replace slack time with a lower cruising velocity • Allows buses to speed up to make up lost time • Buses can slow down if they get too far ahead • Trade off travel time for stability • Lower average velocity (maybe) but lower variance • Users have a higher cost for waiting time than for travel time

17. Possible Methods of Stabilization • Spring based stabilization • Springs connecting adjacent buses • k = spring constant • ‘force’ based on spacing or headway • F = k(hi – hi+1) • v = vt + k Dt hi – k Dt hi+1 • Unscheduled stabilized headways

18. Model Description • State Space: • yi(t) - spacing • hi(t) - headway • Variables • l - demand • b - loss time per pax • vt - target speed • E[vi(t)] = vt/(1+vtlbhi(t)) • Control: vt replaced by vi(hi(t),hi+1(t), yi(t),yi+1(t))

19. Testing the Model • Simulation • Simple simulation • Moves buses according to calculated velocity • Picks up and drops off pax • Real Data • Faux bus route with students as ‘bus drivers’ • Real bus route in Gothenburg, Sweden

20. Future Work • Additional areas of analysis and development • Traffic • Bus velocity constrained by traffic • Parallel Bus routes • Model interaction between overlapping routes? • Create platoons? • TSP/stoplights • Handicap passengers

21. Logistics of City Evacuation Volvo Summer Workshop July 24, 2006 Stella So

22. Immobile Car-less; Challenged Car-owners New Orleans, LA 3 weeks later… Houston, TX

23. Minimize { “evacuation time” } • Increase capacity • Contra flow • Alternate routes • Bottleneck clearance • Manage demand • Multi-modal • ↑ pax per car • ↓ “shadow” evacuation

24. Houston – a disaster for car-owners A Cut-Set Analysis… 19 h 23 h 8 h 6 h

25. We could’ve done MUCH better!

26. Road User Adaptation to Road Safety Measures Presented by: Offer Grembek

27. Road Safety and Road Safety Measures Generic risk factors Physical / Behavioral No Danger Danger Road Safety

28. Road Safety and Road Safety Measures Road Safety Measures (RSM) Generic risk factors Physical / Behavioral “Engineered effect” No Danger Danger Road Safety

29. Road Safety and Road Safety Measures Road Safety Measures (RSM) Generic risk factors Physical / Behavioral “Engineered effect” “Behavioral adaptation” No Danger Danger Road Safety

30. Behavioral Adaptation • What is behavioral adaptation • Seatbelts • All-red interval • Current theories about behavioral adaptation • Risk compensation theories (Wilde) • Potential Benefits • Road safety measures design and evaluation • Academic

31. Research Question Is the effectiveness of RSM influenced by an identifiable road-user behavioral adaptation? • Are there specific types of RSM that generate behavioral adaptation? • Are there specific conditions that generate behavioral adaptation? • Do these behavioral adaptations have a significant impact on the effectiveness of RSM? • How does the impact of these behavioral adaptations change over time?

32. Road Safety and Behavioral Adaptation • Inconsistencies in RSM and behavioral adaptation • Mandatory seat-belts • Center high mounted stoplights • Setbacks of using RSM studies • Statistical validity (confounding, regression-to-the-mean) • Insufficient data

33. The Potential of a Different Approach • Industrial safety and security • Detailed longitudinal data • Immediate consequences • Tradeoff between safety and productivity • Epidemiology • Heterogeneous study population • No visible benefits of compliance • Non-compliance due to thrill (safe-sex) • Portfolio theory • Human behavior under risk

34. Future Work Carlos Daganzo

35. Future Work – Data Needs

36. Transit/City Structure Buses - Small

37. Transit/City Structure Buses - Medium

38. Transit/City Structure Rail - Small

39. Transit/City Structure Rail - Large