0
Bus Rapid Transit and Traffic Safety
Luis Antonio Lindau, Director, EMBARQ Brasil
Nicolae Duduta, Associate Transport Plan...
The impact of BRT systems on traffic safety
Factors that influence safety on BRT corridors
Relationship between safety and...
Mexico CityGuadalajara
Bogota
Curitiba
Porto Alegre
Istanbul
Delhi
Ahmedabad
Vancouver
Brisbane
Rio, SP, BH
PereiraCali
In...
The impact of BRT systems on traffic safety
Factors that influence safety on BRT corridors
Relationship between safety and...
Overall safety impact of a BRT
Case study: Macrobús, Guadalajara
Calz. Independencia, 2007 (before BRT implementation)
Overall safety impact of a BRT
Case study: Macrobús, Guadalajara
Reduction in the number of lanes
Shorter pedestrian
cross...
Monthly crashes before and after the implementation of the BRT
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
0
50
100...
Impact on crashes by severity, per year
Impact on traffic fatalities
Annual fatalities in absence of BRT Annual fatalities...
5000
3194
1 BRT lane
2 general traffic lanes
Passenger per hour per direction (peak)
6
726
1 BRT lane
2 general traffic la...
Overall safety impact of a BRT
Case study: TransOeste, Rio de Janeiro
Av. das Americas 2010 Av. das Americas 2012
Overall safety impact of a BRT
Case study: TransOeste, Rio de Janeiro
The layout of the BRT
is very similar to
Macrobus – ...
Impact on safety?
There is not yet enough data available to evaluate
TransOeste
However, the data so far show between 1.5 ...
BRTs have the potential to significantly improve safety on
the streets where they are implemented
BRT systems where reduct...
The impact of BRT systems on traffic safety
Factors that influence safety on BRT corridors
Relationship between safety and...
Methodology
Crash frequency models
Road safety inspections
Discussions with BRT agency safety and operations staff
Factors...
Statistical models that aim to explain the differences in
crash frequencies (or crash rates) at different locations (e.g.
...
Crash frequency models
Variables (Xi) Coefficients (α, βi) P
Annual average daily traffic (AADT, thousands of vehicles) 0....
Factors influencing crash frequencies
Counterflow
Counterflow lanes were strongly correlated with higher
crash frequencies...
Factors influencing crash frequencies
Street width and intersection size and complexity
Metrobus Line 1, Mexico City
Road ...
Factors influencing crash frequencies
Location of bus lanes
Central median
Shorter pedestrian crossings
Fewer mixed traffi...
The safety impact of large blocks
For each additional 10 m (30’) between signalized
intersections:
• 2% decrease in all cr...
Wider streets are more problematic for safety
Wide, complex intersections can easily become “black
spots”
The length of cr...
A detailed inspection of a street with the objective of
identifying safety issues
Involves walking along the entire length...
Fatalities on BRT corridors by road user type
Fatalities by
Road User
Type
0%
Pedestrians
54%Car occupants
23%
Motorcyclis...
Crossing in mid-block
Mid-block signalized crosswalk - TransOeste
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
Pedestrian signal timing
BRT Safety recommendations
41 41
SPEED REDUCTIONS: PEDESTRIAN CROSSINGS: INCREASED SIGNAL TIME:
To increase safety on Av. ...
Speed at Avenida das Américas
42
Speed
• It is very difficult to control speed through signage and enforcement
• Streets should be designed for their desir...
Pedestrian bridges
Pedestrian bridges rarely work, as pedestrians prefer to cross under them
In some cases, this is due to...
Improving the BRT routes
Based on EMBARQ’s recommendations…
• Stations barriers were improved to avoid unregulated and uns...
2011: Signalized mid-block crossing on Eje 2
Oriente, with no traffic calming. Vehicles did not
stop for pedestrians.
2012...
There is often a considerable difference between how
streets are meant to be used and how people actually use
them:
Jaywal...
The impact of BRT systems on traffic safety
Factors that influence safety on BRT corridors
Relationship between safety and...
Most safety recommendations involved speed reductions,
traffic calming, or additional traffic signals
This raises the ques...
The relationship between safety and operational performance
TransOeste BRT, Rio de Janeiro, Brazil
Methodology
Identified ...
The relationship between safety and operational performance
TransOeste BRT, Rio de Janeiro, Brazil
Main safety issues:
Hig...
The relationship between safety and operational performance
TransOeste BRT, Rio de Janeiro, Brazil
Main safety recommendat...
The relationship between safety and operational performance
TransOeste BRT, Rio de Janeiro, Brazil
Indicator Service Basel...
The relationship between safety and operational performance
TransOeste BRT, Rio de Janeiro, Brazil
* Speed variability is ...
More resources on this topic
WCTR Presentation:
C4-6 Public Transport Safety (Slot 6g/Room g/13:40-15:20 Tue.)
More detail...
Thank you
Luis Antonio Lindau, tlindau@embarqbrasil.org
Nicolae Duduta, nduduta@wri.org
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BRT Workshop - Bus Rapid Transit and Traffic Safety

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O Centro de Excelência em BRT Across Latitudes and Cultures (ALC-BRT CoE) promoveu o Bus Rapid Transit (BRT) Workshop: Experiences and Challenges (Workshop BRT: Experiências e Desafios) dia 12/07/2013, no Rio de Janeiro. O curso foi organizado pela EMBARQ Brasil, com patrocínio da Fetranspor e da VREF (Volvo Research and Education Foundations).

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Transcript of "BRT Workshop - Bus Rapid Transit and Traffic Safety"

  1. 1. Bus Rapid Transit and Traffic Safety Luis Antonio Lindau, Director, EMBARQ Brasil Nicolae Duduta, Associate Transport Planner, EMBARQ July 12, 2013
  2. 2. The impact of BRT systems on traffic safety Factors that influence safety on BRT corridors Relationship between safety and operational performance Summary
  3. 3. Mexico CityGuadalajara Bogota Curitiba Porto Alegre Istanbul Delhi Ahmedabad Vancouver Brisbane Rio, SP, BH PereiraCali In Brazil it comprised: road safety audits and inspections in 5 cities 190 km of corridors more than 2 million pax per day A global study
  4. 4. The impact of BRT systems on traffic safety Factors that influence safety on BRT corridors Relationship between safety and operational performance Summary
  5. 5. Overall safety impact of a BRT Case study: Macrobús, Guadalajara Calz. Independencia, 2007 (before BRT implementation)
  6. 6. Overall safety impact of a BRT Case study: Macrobús, Guadalajara Reduction in the number of lanes Shorter pedestrian crossings Central median Existing buses and minibuses replaced with a single operating agency
  7. 7. Monthly crashes before and after the implementation of the BRT 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 0 50 100 150 200 250 Jan-07 Mar-07 May-07 Jul-07 Sep-07 Nov-07 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar-09 May-09 Jul-09 Sep-09 Nov-09 Jan-10 Mar-10 May-10 Jul-10 Sep-10 Nov-10 Jan-11 Mar-11 May-11 Monthlycitywidecrashes(excludingtheBRTcorridor) MonthlycrashesontheBRTcorridor Citywide Crashes on the BRT Before During BRT construction During BRT
  8. 8. Impact on crashes by severity, per year Impact on traffic fatalities Annual fatalities in absence of BRT Annual fatalities with BRT Change in fatalities Baseline data Modeled baseline data Project data Modeled project data Macrobus BRT 1 3.5 0.3 1 - 2.5 Impact on traffic injuries Annual traffic injuries in absence of BRT Annual injuries with BRT Change in injuriesBaseline data Project data Macrobus BRT 96.8 30 - 66.8 Impact on all crashes Annual crashes in absence of BRT Annual crashes with BRT Change in crashesBaseline data Project data Macrobus BRT 2,341 1,010 - 1,331
  9. 9. 5000 3194 1 BRT lane 2 general traffic lanes Passenger per hour per direction (peak) 6 726 1 BRT lane 2 general traffic lanes Crashes per year Comparison between the bus lanes and the mixed traffic lanes
  10. 10. Overall safety impact of a BRT Case study: TransOeste, Rio de Janeiro Av. das Americas 2010 Av. das Americas 2012
  11. 11. Overall safety impact of a BRT Case study: TransOeste, Rio de Janeiro The layout of the BRT is very similar to Macrobus – center lanes, median stations, overtaking lanes But the street is considerably wider (up to 100 m) and speed limits are as high as 80kmh
  12. 12. Impact on safety? There is not yet enough data available to evaluate TransOeste However, the data so far show between 1.5 and 4.5 fatalities per month on Av. das Americas in 2012, some of them involving BRT vehicles, which could mean an increase in fatalities after BRT implementation
  13. 13. BRTs have the potential to significantly improve safety on the streets where they are implemented BRT systems where reductions in injuries and fatalities have been observed include Macrobus (Guadalajara), Metrobus (Mexico City), TransMilenio (Bogota), Janmarg (Ahmedabad) Reductions range from 30% (Metrobus) to 70% (Macrobus) But some systems have seen increases in fatalities (Delhi) or have a concerning number of fatalities (TransOeste) Overview of safety impacts
  14. 14. The impact of BRT systems on traffic safety Factors that influence safety on BRT corridors Relationship between safety and operational performance Summary
  15. 15. Methodology Crash frequency models Road safety inspections Discussions with BRT agency safety and operations staff Factors that influence safety on BRT corridors
  16. 16. Statistical models that aim to explain the differences in crash frequencies (or crash rates) at different locations (e.g. intersections) using variables related to geometry, traffic volumes, land use, etc. Commonly use a Poisson or negative binomial (Poisson- Gamma) distribution Crash frequency models
  17. 17. Crash frequency models Variables (Xi) Coefficients (α, βi) P Annual average daily traffic (AADT, thousands of vehicles) 0.016 0.074 Total length of all approaches to the intersection (L, meters) 0.003 0.010 Average number of lanes per approach 0.334 0.000 Cross street is through street (=1 if yes, =0 otherwise) 1.142 0.029 Major T junction (=1 if yes, =0 otherwise) 0.719 0.019 Constant -3.914 0.000 N = 133, LR χ2 (prob.) = 64.62 (0.000), Log likelihood = -141.580 Variables (Xi) Coefficients (α, βi) P Presence of a center median (=1 if yes, =0 otherwise) -0.349 0.004 Total number of approaches to the intersection (m) 0.424 0.000 Average length of approaches to the intersection (Lavg, meters) -0.008 0.036 Average number of lanes per approach 0.492 0.000 Cross street is through street (=1 if yes, =0 otherwise) 0.820 0.000 Major T junction (=1 if yes, =0 otherwise) 0.748 0.008 Constant -1.197 0.002 N = 132, LR χ 2 (prob.) = 135.76 (0.000), Log likelihood = -141.580, chibar2 (prob.) = 341.99 (0.000) Table 1: Severe crash frequency model for Guadalajara (Poisson) Table 2: All crash frequency model for Guadalajara (negative binomial)
  18. 18. Factors influencing crash frequencies Counterflow Counterflow lanes were strongly correlated with higher crash frequencies across all our models
  19. 19. Factors influencing crash frequencies Street width and intersection size and complexity Metrobus Line 1, Mexico City Road width and complexity of intersections were the most important predictors of crash frequencies.
  20. 20. Factors influencing crash frequencies Location of bus lanes Central median Shorter pedestrian crossings Fewer mixed traffic lanes Some 4-way intersections turned into T junctions
  21. 21. The safety impact of large blocks For each additional 10 m (30’) between signalized intersections: • 2% decrease in all crashes • 3% increase in severe crashes
  22. 22. Wider streets are more problematic for safety Wide, complex intersections can easily become “black spots” The length of crosswalks is key for pedestrian safety (for each additional meter a pedestrian needs to cross without a median, there is a 2 to 3% increase in pedestrian crashes) Counterflow is the most dangerous bus lane configuration Overview of findings from data analysis
  23. 23. A detailed inspection of a street with the objective of identifying safety issues Involves walking along the entire length of a study site (in our case, a BRT corridor) documenting problems related to infrastructure and road user behavior Road safety inspections
  24. 24. Fatalities on BRT corridors by road user type Fatalities by Road User Type 0% Pedestrians 54%Car occupants 23% Motorcyclists 10% Bicyclists 5% Other 8% The safest place to be on a bus corridor is inside the bus The most dangerous: pedestrian crossing the avenue
  25. 25. Crossing in mid-block
  26. 26. Mid-block signalized crosswalk - TransOeste
  27. 27. Pedestrian signal timing
  28. 28. Pedestrian signal timing
  29. 29. Pedestrian signal timing
  30. 30. Pedestrian signal timing
  31. 31. Pedestrian signal timing
  32. 32. Pedestrian signal timing
  33. 33. Pedestrian signal timing
  34. 34. Pedestrian signal timing
  35. 35. Pedestrian signal timing
  36. 36. Pedestrian signal timing
  37. 37. Pedestrian signal timing
  38. 38. Pedestrian signal timing
  39. 39. Pedestrian signal timing
  40. 40. Pedestrian signal timing
  41. 41. BRT Safety recommendations 41 41 SPEED REDUCTIONS: PEDESTRIAN CROSSINGS: INCREASED SIGNAL TIME: To increase safety on Av. das Americas, EMBARQ proposed…
  42. 42. Speed at Avenida das Américas 42
  43. 43. Speed • It is very difficult to control speed through signage and enforcement • Streets should be designed for their desired speed
  44. 44. Pedestrian bridges Pedestrian bridges rarely work, as pedestrians prefer to cross under them In some cases, this is due to the fear of crime (e.g. research in Cape Town showing pedestrians are concerned of being assaulted or robbed on overpasses) Our research shows they are not effective for safety on typical urban arterials - no significant impact on pedestrian crash frequencies The exception is on high-speed, high-volume roads (e.g. Autopista Norte, Bogota, where locations with pedestrian bridges had four times fewer pedestrian crashes
  45. 45. Improving the BRT routes Based on EMBARQ’s recommendations… • Stations barriers were improved to avoid unregulated and unsafe pedestrian crossings • Install lateral barriers in the platform doors • The city is studying to reduce speed limits from 80km/h to 60 km/h in Avenida das Américas
  46. 46. 2011: Signalized mid-block crossing on Eje 2 Oriente, with no traffic calming. Vehicles did not stop for pedestrians. 2012: Speed hump installed before the pedestrian crossing, slowing traffic down and allowing pedestrian to cross safely. More closely spaced signalized intersections can help avoid unsafe speeds But drivers may disregard signals where the only conflict is with pedestrians Speed reductions
  47. 47. There is often a considerable difference between how streets are meant to be used and how people actually use them: Jaywalking, including crossing under pedestrian bridges, jumping over guardrails, destroying guardrails Crossing on red (pedestrians) or driving on red (drivers) The key to designing safer streets is understanding road user behavior and how the design of the infrastructure can be better adapted to that Overview of findings from inspections
  48. 48. The impact of BRT systems on traffic safety Factors that influence safety on BRT corridors Relationship between safety and operational performance Summary
  49. 49. Most safety recommendations involved speed reductions, traffic calming, or additional traffic signals This raises the question of how safety countermeasures would impact the operational performance of a BRT We illustrate the relationship between safety and operational performance with a case study from TransOeste Safety, operations, and capacity
  50. 50. The relationship between safety and operational performance TransOeste BRT, Rio de Janeiro, Brazil Methodology Identified safety issues Proposed countermeasures Applied a microsimulation model to test the impact of safety countermeasures on: Operating speeds Travel times Speed variability
  51. 51. The relationship between safety and operational performance TransOeste BRT, Rio de Janeiro, Brazil Main safety issues: High speed road: 80 km/h speed limit Few crossing opportunities for pedestrians Jaywalking is a common problem
  52. 52. The relationship between safety and operational performance TransOeste BRT, Rio de Janeiro, Brazil Main safety recommendations: Lowering the speed limit to 60 km/h Adding mid-block signalized crossings Improving signal timing to reduce pedestrian delay
  53. 53. The relationship between safety and operational performance TransOeste BRT, Rio de Janeiro, Brazil Indicator Service Baseline 60 km/h 60/30 km/h Complete Speed (km/h) Express 32 31.5 29.6 29.6 Local 25.6 25.6 25.4 25.4 Travel time (min) Express 71 72 77 77 Local 89 89 89 89 Speed variability* Express 0.19 0.18 0.16 0.16 Local 0.16 0.15 0.15 0.16 * Speed variability is defined here as the ratio of the standard deviation to the mean commercial speed, for all vehicles generated in the simulation. A lower speed variability coefficient indicates more reliable service. Key finding: Slight negative impact on operating speed and travel time
  54. 54. The relationship between safety and operational performance TransOeste BRT, Rio de Janeiro, Brazil * Speed variability is defined here as the ratio of the standard deviation to the mean commercial speed, for all vehicles generated in the simulation. A lower speed variability coefficient indicates more reliable service. Key findings: Potential for significant safety benefits No impact on passenger capacity Magnitude of operational impacts negligible compared to safety benefits Performance indicator Baseline Project Change Source All crashes n/a n/a -15% to -67% Elvik and Vaa 2004 Operating speed 32 km/h 29.6 km/h -2.4 km/h Microsimulation Travel time 71 min 77 min + 6 min Microsimulation Speed variability 0.19 0.16 - 0.03 Microsimulation Capacity (pphpd) 18,800 18,800 No impact Based on Hidalgo et al. (2011)
  55. 55. More resources on this topic WCTR Presentation: C4-6 Public Transport Safety (Slot 6g/Room g/13:40-15:20 Tue.) More detailed presentation on the link between safety and operational performance using the TransOeste case study Publications available online: Understanding the Road Safety Impact of High Performance BRT and Busway Design Features Technical paper including the methodology and main findings from the crash frequency models shown here Available online at: http://www.brt.cl/understanding-road-safety-impact-of- high-performance-bus-rapid-transit-and-busway-design-features-2/ Traffic Safety on Bus Corridors Safe design concepts for BRT and Busways Available online at: http://www.embarq.org/en/traffic-safety-bus-corridors- pilot-version-road-test (English, Spanish, Portuguese)
  56. 56. Thank you Luis Antonio Lindau, tlindau@embarqbrasil.org Nicolae Duduta, nduduta@wri.org
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