Safety impact from bus rapid transit, factors impacting safety performance on a bus corridor, impact of safety countermeasures on operational performance. Case studies from Delhi, Bogota TransMilenio, Rio de Janeiro TransOeste.

1. Traffic Safety on Bus Corridors
Nicolae Duduta
EMBARQ, World Resources Institute
ALC BRT Center of Excellence Webinar
September 27, 2013 11am EST
Please mute your microphones

2. What is the overall safety impact from implementing a BRT,
Busway, or other type of bus system?
What are the factors that impact safety performance on a
bus corridor?
How do safety countermeasures impact operational
performance?
Case studies
Summary

3. Depends on the configuration of the new bus system,
but also on what was there before
Here: Calz. Independencia (Guadalajara) before BRT
Overall safety impact

4. Overall safety impact
Reduction in the number of
lanes
Shorter
pedestrian
crossings
Central
median
Existing buses and minibuses
replaced with a single
operating agency

6. Overall safety impact

7. Overall safety impact

8. What is the overall safety impact from implementing a BRT,
Busway, or other type of bus system?
What are the factors that impact safety performance on
a bus corridor?
How do safety countermeasures impact operational
performance?
Summary

9. Crash frequency models
Statistical models that aim to explain differences in crash
rates at different locations through variables including traffic
volumes, street geometry, land uses, etc.
The preferred probability distributions for modeling crash
data are Poisson and, more commonly, negative binomial
The same street characteristic (e.g. block sizes) will have
different impacts on crashes at different levels of severity
It is recommended to develop crash frequency models for
different types of crashes (e.g. vehicle collisions, pedestrian
crashes, severe crashes, property damage crashes, etc.)

10. Crash frequency model results
Guadalajara

11. Crash frequency model results
Mexico City
Safety impact analysis showed statistically significant safety improvements post
BRT implementation

12. Crash frequency model results
Removal of one
lane per
approach: -28%
crashes
Crosswalk
shortened by 10m:
-26% pedestrian
crashes
Central median:
-28% vehicle collisions
Left turn
prohibitions:
-20% all crash
types

13. The safest place to be on a bus corridor is inside the bus
The most dangerous place: walking to and from the station
Fatalities on bus corridors
Fatalities by
Road User
Type
0%
Pedestrians
54%
Car
occupants
23%
Motorcyclists
10%
Bicyclists
5% Other
8%

14. Delhi Busway
Traffic speeds and block sizes
For each additional 10 m (30’) between signalized
intersections:
• 2% decrease in all crashes
• 3% increase in severe crashes

15. TransMilenio, Av. Caracas, Bogota
Traffic speeds and block sizes

16. TransOeste BRT, Rio de Janeiro
Traffic speeds and block sizes

17. Av. das America, Rio de Janeiro
Speed management
Av. Caracas, Bogota

18. Metrobus Line 2, Mexico City
Pedestrians do not use bridges and prefer to cross under them
Crash frequency model: bridges have no statistically significant
impact on pedestrian safety on urban arterials
Pedestrian bridges

19. Metrobus BRT, Istanbul
Pedestrian bridges are a good solution on expressways
Crash frequency model: bridges are strongly correlated with lower
pedestrian crash frequencies on expressways
Pedestrian bridges

20. Curbside bus lane, Eje 2 Oriente, Mexico City
Mid-block signalized crosswalks

21. What is the overall safety impact from implementing a
BRT, Busway, or other type of bus system?
What are the factors that impact safety performance on a
bus corridor?
How do safety countermeasures impact operational
performance?
Summary

22. Case study: TransOeste BRT, Rio de Janeiro
Road safety inspection – proposed safety countermeasures
targeted at speed reductions and improved pedestrian safety
Microsimulation model – test the impact of countermeasures
on operational performance

23. Safety recommendations
Reducing speed from 70kmh to 60kmh (30 kmh at stations)
Adding mid-block signalized crossings
Reducing pedestrian signal delay

24. Pedestrian delay issues - TransOeste
Mid-block signalized crosswalk, Av. das Americas

25. Pedestrian delay issues - TransOeste
Mid-block signalized crosswalk, Av. das Americas

26. Pedestrian delay issues - TransOeste
HCM recommends keeping pedestrian delay under 30 seconds (ideally under 10)

27. Impact on operations
* 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.
Slight negative impact on commercial speed (though still above 25kmh
benchmark)
Slight increase in travel times (+6 min terminal to terminal)
Lower speed variability (i.e. more reliable service)
Potential for significant safety benefits

29. Nicolae Duduta, nduduta@wri.org
EMBARQ.org
Further reading on this topic:
EMBARQ’s safe design guidelines for BRT:
http://www.embarq.org/en/traffic-safety-bus-corridors-pilot-version-road-
test
A TRR paper including the crash frequency models:
http://www.brt.cl/understanding-road-safety-impact-of-high-performance-
bus-rapid-transit-and-busway-design-features-2/
Next steps