Volvo Summer Workshop Track 2: Urban Transportation Physics

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Volvo Summer Workshop Track 2 Urban
Transportation Physics

• Carlos Daganzo

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Outline

• Focus
• Mass motions in cities
• How things work?
• New technologies
• New policies

• Projects
• BLIPS
• Green Logistics
• Gridlock
• Self synchronizing buses
• Evacuation
• Safety

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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
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Complexity Fades Away
Results do not rely on particulars of how the
cocoon is achieved.
One example of cocoon formation.
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Green Logistics Implemented schemes
Category Implemented Policy
Restriction zones 1. Copenhagen - City Goods Ordinance for capacity management
Restriction zones 2.Sweden - Environmental Zones
Restriction zones 3. UK - Low Emission Zones
Restriction zones 4. Brussels Lorry dedicated routes
Clean vehicles 5. Rotterdam - Electric Vehicle City Distribution System
Clean vehicles 6. Osaka - Electric Vans
Clean vehicles 7. Zurich-Cargo Tram
Coordinated transport 8. Berlin - Goods Traffic Platform (Public Private Partnership)
Coordinated transport 9. Stockholm - logistical centre for coordinated transports
Congestion mitigation 10. Barcelona - Multiple Use Lanes on line parking information
Congestion mitigation 11. Paris, Barcelona, Rome - Night delivery schemes
Charging 12. London Congestion Charging
Charging 13. Germany - Truck Toll System
Information systems 14. New York and Vancouver - Internet Port Information Systems
Information systems 15. Tokyo Advanced Information Systems
Water use 16. Amsterdam - Floating Distribution Centre
Water use 17. Venice - Waterborne traffic management decision support system
Geroliminis and Daganzo (2005), A review of green
logistics schemes used in cities around the world
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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
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Clean vehicles
combining an efficient goods distribution concept
with the environmental impact of electric vehicle
transport
Rotterdam - ELectric vehicle CIty DIstribution
System

• 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.

Total Cost 1.2 million EURO
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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)

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Gridlock In Cities

• Nikolas Geroliminis

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Self-Stabilizing Bus Routes

• Josh Pilachowski

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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

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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

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Control Methods

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

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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

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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 dont like sitting on the side of the
  road
• Station Control ? Interstation Control
• Continuous control points become speed control

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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

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Possible Methods of Stabilization

• Spring based stabilization
• Springs connecting adjacent buses
• k spring constant
• force based on spacing or headway
• F k(hi hi1)
• v vt k Dt hi k Dt hi1
• Unscheduled stabilized headways

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Model Description

• State Space
• yi(t) - spacing
• hi(t) - headway
• Variables
• l - demand
• b - loss time per pax
• vt - target speed
• Evi(t) vt/(1vtlbhi(t))
• Control vt replaced by vi(hi(t),hi1(t),
  yi(t),yi1(t))

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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

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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

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Logistics of City Evacuation

• Volvo Summer Workshop
• July 24, 2006
• Stella So

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Immobile Car-less Challenged Car-owners
New Orleans, LA
3 weeks later
Houston, TX
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Minimize evacuation time

• Increase capacity
• Contra flow
• Alternate routes
• Bottleneck clearance

• Manage demand
• Multi-modal
• ? pax per car
• ? shadow evacuation

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Houston a disaster for car-owners
A Cut-Set Analysis
19 h
23 h
8 h
6 h
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We couldve done MUCH better!
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Road User Adaptation to Road Safety Measures

• Presented by
• Offer Grembek

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

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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?

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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

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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

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Future Work

• Carlos Daganzo

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Future Work Data Needs
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Transit/City Structure
Buses - Small
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Transit/City Structure
Buses - Medium
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Transit/City Structure
Rail - Small
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Transit/City Structure
Rail - Large