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Juan Carlos Muñoz - Connected and automated buses. An opportunity to bring reliability to bus service.

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Connected and automated trains have been successfully built for decades. And connected and automated cars are promising to become a reality in our streets in the next decade. What about buses? What are the benefits of having buses connected and automated too? This talk will analyse some of these benefits focusing on the prospect of avoiding bus bunching and the impact this may have in the level of service of bus users.

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Juan Carlos Muñoz - Connected and automated buses. An opportunity to bring reliability to bus service.

  1. 1. Connected and automated buses. An opportunity to bring reliability to bus service Juan Carlos Muñoz Dept. of Transport Engineering and Logistics Pontificia Universidad Católica de Chile @JuanCaMunozA
  2. 2. What do we understand by automated vehicles? What do we understand by connected vehicles?
  3. 3. Autonomous buses? Connected buses?
  4. 4. Autonomous buses? Connected buses? • Does it make sense? • Where are the benefits? • Is it really possible?
  5. 5. Autonomous public transport has been around for decades
  6. 6. • Modern Metro systems are driverless or have drivers that do not drive • And driverless cars are already here…. • This innovation seems to be ignoring buses. • If we consider automation in buses…. • which should be the first step for buses towards automation?
  7. 7. •Driverless Metro seem feasible because of rails and a fully segregated way. Buses lack rails But…
  8. 8. The conflicts with other vehicles and pedestrians for a bus in a corridor are much easier to predict than for a car moving in regular traffic
  9. 9. • Thus, automatizing buses should start with buses operating in corridors. • According to www.brtdata.org there are 452 BRT corridors in 205 cities worldwide, serving more tan 34 million passengers per day. • The benefits from automatizing for these passengers would be huge. • A centralized coordinating control can become the rails for these buses and much more
  10. 10. Some potential benefits of automated and controlled operation Smoother bus docking at stations Safety Traffic signal priority Eco-driving Schedules (waiting times and transfers) Headway regularity
  11. 11. What do people seek when travelling in public transport? Fast Low waits Comfortable Reliable
  12. 12. How can we achieve these attributes? DECREASE TRAVEL TIME INCREASE FREQUENCY INCREASE FLEET OR INCREASE SPEED INCREASE TRANSPORT CAPACITY DECREASE TRAVEL TIME VARIABILITY Fast Low waits Comfortable Reliable INCREASE SPEED INCREASE FLEET, VEHICLE SIZE OR INCREASE SPEED REGULAR HEADWAYS
  13. 13. How can we achieve these attributes? Fast Low waits Comfortable Reliable INCREASE SPEED! AND THEN MAYBE IF WE HAVE SPARE TIME FOCUS ON REGULAR HEADWAYS….
  14. 14. How can we achieve these attributes? Fast Low waits Comfortable Reliable I N C R E A S E S P E E D A N D R E G U L A R H E A D W A Y S !
  15. 15. Vehicles in public transport systems behave like magnets…. Any perturbation and the equilibrium is lost… all around the world. Regular intervals is an unstable equilibrium
  16. 16. Bus bunching… found in London
  17. 17. Bus bunching… found in Beijing
  18. 18. Bus bunching… found in Santiago
  19. 19. Today we will address three questions Why does bus bunching happen? What are the impacts? 1 2 Does it have a solution?3
  20. 20. Why does bus bunching happen? • Dispatch strategy • Speed variability • Travel time variability • Dwell time variability
  21. 21. Why does bus bunching happen? Time (minutes) Position (km)
  22. 22. Why does bus bunching happen? • Dispatch strategy • Speed variability • Travel time variability • Dwell time variability
  23. 23. Why does bus bunching happen? Congestion Traffic lights Driver heterogeneity Travel time variability
  24. 24. Why does bus bunching happen? Stochastic passenger arrivals at each stop Capacity of buses and stops Dwell time variability
  25. 25. Today we will address three questions Why does bus bunching happen? What are the impacts? 1 2 Does it have a solution?3
  26. 26. What are the impacts? Impacts are various, affecting: Users Operators
  27. 27. What are the impacts? 8:00 8:05 8:10 8:15 8:20 8:00 8:02 8:10 8:12 8:20
  28. 28. What are the impacts? • Waiting times grow • One minute of waiting is perceived as two or three minutes of in-vehicle time • Waiting times variability grow • Leads to earlier departures for users
  29. 29. What are the impacts? • Average crowdedness grow • Longer waiting times correlate with high occupancy • More users suffer high occupancy • Users tend to remember the worst experiences
  30. 30. What are the impacts? • Dwell times grow • Boarding and alighting is slow creating friction that damages the experience • Speed drops…. And capacity drops • Cycle times variability grows • Operators need extra fleet and drivers due to variable cycle times
  31. 31. What are the impacts? User Satisfaction Occupancy In bus services user satisfaction with the in- vehicle experience drops as occupancy inside the vehicle grows.
  32. 32. What are the impacts? User Satisfaction Occupancy Imagine a service that must be provided at a stop where passengers arrive at 10 passengers/min. We plan a 5 minute interval service. Each bus will arrive empty and therefore should leave with 50 passengers. If bus capacity is 80 passengers then we get 63% occupancy.
  33. 33. What are the impacts? User Satisfaction Occupancy63% 80%
  34. 34. What are the impacts? User Satisfaction Occupancy63% 80% Suppose the service is not regular, and operates with intervals of 2 and 8 minutes alternately (with occupancies of 25% and 100% respectively). 90% 25% 100% 10%
  35. 35. What are the impacts? User Satisfaction Occupancy63% 80% 90% 25% 100% Average occupancy of buses will still be 63%, with an apparent satisfaction of 50%. 50% 10%
  36. 36. What are the impacts? User Satisfaction Occupancy63% 80% 90% 25% 100% 50% 85% 26% 10% However, it is not the average satisfaction among buses that matters, it is the average satisfaction across passengers!
  37. 37. What are the impacts? User Satisfaction Occupancy63% 80% 90% 25% 100% Average occupancy perceived by users will be 85%, with a satisfaction level of only 26%!50% 85% 26% 10% However, it is not the average satisfaction among buses that matters, it is the average satisfaction across passengers!
  38. 38. What are the impacts? User Satisfaction Occupancy63% 80% 90% 25% 100% 50% 85% 26% 10% This is what we planned for… 80% satisfaction This is what we achieved with no coordination and control! 26% satisfaction
  39. 39. How can we achieve these attributes? Fast Low waits Comfortable Reliable I N C R E A S E S P E E D A N D R E G U L A R H E A D W A Y S !
  40. 40. Today we will address three questions Why does bus bunching happen? What are the impacts? 1 2 Does it have a solution?3
  41. 41. Does it have a solution? •Yes! • Dedicated infrastructure • Transit signal priority • Real-time control at dispatching and along the route
  42. 42. Does it have a solution?
  43. 43. Does it have a solution? Source: mto.gov.on.ca
  44. 44. Does it have a solution? Ok! Hold Go faster (if possible) Slow down
  45. 45. Does it have a solution? No control With control Color indicates bus load! Delgado et al, 2012
  46. 46. Does it have a solution?
  47. 47. in Transantiago $- $100 $200 $300 $400 $500 $600 Week 1 Week 2 Week 3 Week 4 Week 5 Week 8 Week 9 Week 10 Week 11 Week 12 Week 13 Week 14 Week 15 Week 16 Week 17 B14 + B22 Otubound Fines at Dispatching Point - 2017 Fines
  48. 48. Transmilenio in Bogota 0 10 20 30 40 50 60 70 80 90 100 C84tiemposdeciclo Tpo Ciclo con Control (14 Abril + 26 Mayo) Tpo Ciclo sin Control (21 Abril + 25 Mayo) With driver assistance: cycle time = 63,4 min & Std Dev = 5,6 min Without driver assistance: cycle time = 69,5 min & Std Dev = 11,8 min With driver assistance : April 14 + May 26 Without driver assistance : April 21 + May 25
  49. 49. Cincinnati Streetcar Route 5 - Malmö BRT • 5 streetcars • 12 minute headway • 16 BRT buses • 5 minute headway
  50. 50. Open versus closed BRT • Some cities are operating open BRT corridors in which buses join and leave the corridor providing a direct trip for some journeys. • In such cases the driver should only drive while the bus is not in the corridor.
  51. 51. Notice that drivers are the critical link…. • We have shown that (Phillips et al, 2014) it takes few drivers not obeying instructions systematically to severely damage the benefits of automated and coordinated control. • In the path towards automatizing…put buses first!
  52. 52. Connected and automated buses. An opportunity to bring reliability to bus service Juan Carlos Muñoz Dept. of Transport Engineering and Logistics Pontificia Universidad Católica de Chile @JuanCaMunozA

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