Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
TREC Webinar
22 April, 2015
Impacts of Roadway and
Traffic Characteristics on Air
Pollution Risks for Bicyclists
Alex Biga...
Health Effects of Bicycling
• Health impact studies for walking &
biking have shown that physical
activity benefits outwei...
Framework
3
Vehicle
Emissions
Air
Quality
Traveler
Exposure
Inhalation
Uptake
Health
Effects
Bicyclists' Pollution Uptake
Outline
1. Exposure concentrations
2. Ventilation & inhalation dose
3. Pollutant uptake
4. Applications for transportation...
Bicyclist Exposure
Concentrations
5Urban Bicyclists' Pollution Uptake
Traveler
Exposure
Bicyclists’ Exposures
6
0 5 10 15 20
Ultrafine PM
Fine PM
Coarse PM
Black Carbon
CO
VOC
NO2
# studies measuring on-road
bi...
Modal Comparisons of Exposure
– Is this actionable information?
Context-dependent results
– Bicyclists lower if separated
...
High-Traffic/Low-Traffic Routes
8Bicyclists' Pollution Uptake
-50%
0%
50%
100%
150%
200%
250%
CO VOC UFP PM2.5 PM10 BC
Exp...
PSU Bike Exposure Research
9Urban Bicyclists' Pollution Uptake
How can we reduce
exposure risks for bicyclists?
Sampling Equipment
10Bicyclists' Pollution Uptake
11
Exposure Data coverage
Urban Bicyclists' Pollution Uptake
Results: VOC Exposure Models
• +2% per 1,000 ADT
• +20-30% in stop-and-go riding
• Off-street path +300% in industrial
cor...
13
Parallel Path Comparison
Bicyclists' Pollution Uptake
E Burnside St. SE Ankeney St.
N Williams Ave. NE Rodney Ave.
Nait...
Bicyclist Pollution
Inhalation
14Urban Bicyclists' Pollution Uptake
Inhalation
Ventilation and Exercise
15Bicyclists' Pollution Uptake
50 100 150 200 250
Watts
Ventilation(liter/min)
75
50
25
Ventilati...
Ventilation & Bicycle Studies
16
57 studies assess
bicyclists’ exposure
Ignored
38
Constant
16
Assumed/
Modeled
15
Measure...
Bicyclist Ventilation
17Urban Bicyclists' Pollution Uptake
0
1
2
3
4
5
0 5 10 15 20
RatioofBicycle/Motorized
TravelerVenti...
Modal Comparisons of Dose
18Urban Bicyclists' Pollution Uptake
-100%
-80%
-60%
-40%
-20%
0%
20%
40%
60%
Pedestrian Car/Tax...
PSU Research Findings
• 4-8% increase in
ventilation per 10 W
• Mean lag
~50 sec
• Highly variable
on-road
19Bicyclists' P...
Bicyclist Pollution
Uptake
20Urban Bicyclists' Pollution Uptake
Uptake
Bicyclist Uptake Studies
2 studies of biomarkers:
• VOC: blood & urine
– Urban bikers > rural bikers
• BC: induced sputum
...
Breath Biomarkers
Exhaled breath is a good proxy for
blood concentrations of VOC
22Bicyclists' Pollution Uptake
alphaszens...
1) Local roads Pre
Breath
Post
Breath
PSU On-Road Sampling
20-30 minutes, 3-5 miles
Exposure & breath VOC
Paired subjects
...
Breath and Exposure Concentrations
0 1 2 3
Breath
Exposure
Concentration (normalized to Park)
Toluene
Major arterials
Loca...
Breath Sampling Results
• The breath sampling method works
– Exposure predicts breath concentrations
– Δ Breath ~ ½ Δ Expo...
Explained variance in breath BTEX
26Bicyclists' Pollution Uptake
0%
10%
20%
30%
40%
50%
Measured variables Modeled variabl...
Exercise and Uptake
• Ventilation/inhalation rate:
2-5x higher
• PM uptake: ≥2-5x higher
• VOC uptake: 1.5-2x higher
27Bic...
Applications
28Bicyclists' Pollution Uptake
Route Choice
• Detour to reduce inhalation dose if:
– <46% longer than minor arterial route
– <123% longer than major arte...
Comparison with Preferences
30Bicyclists' Pollution Uptake
Will bicyclists naturally minimize
inhaled dose over a trip?
Bi...
Inhalation and Stops
31Urban Bicyclists' Pollution Uptake
0
100
200
300
400
500
600
6 8 10 12 14 16 18
Cruise-equivalentex...
Inhalation and Speed
32Bicyclists' Pollution Uptake
0
50
100
150
200
250
300
0 4 8 12 16
Ventilation(l/km)
Speed (mph)
0% ...
Bikeway Design Considerations
Bike lane • Higher-traffic streets
• Some lateral separation
• Dedicated lane reduces stops ...
Take-Away Principles
1. Bicyclist Exposure
a) Many different pollutants
b) Traffic, weather, and land-use all important
c)...
Future Work
• Abstraction for HIA & CBA
• Characterizations of urban bicyclists
• Similar study for pedestrians
• Crowd-so...
Questions?
abigazzi@pdx.edu
alexbigazzi.com
36Bicyclists' Pollution Uptake
Acknowledgments
• Miguel Figliozzi, Jim Pankow,...
37
Industrial Corridor
Bicyclists' Pollution Uptake
Steady-state biking work
38Bicyclists' Pollution Uptake
0
50
100
150
200
250
0 2 3 5 6 8 9 11 13 14 16
Workload(W)
Speed (...
Minimum-Inhalation Speed
39Bicyclists' Pollution Uptake
0
5
10
15
0% 2% 4% 6% 8% 10%
Minimum-ventilation
speed(mph)
Grade
Upcoming SlideShare
Loading in …5
×

Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclist

999 views

Published on

Alex Bigazzi, Ph.D., Portland State University
Webinar date: 2015-04-23

Published in: Education
  • Be the first to comment

  • Be the first to like this

Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclist

  1. 1. TREC Webinar 22 April, 2015 Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclists Alex Bigazzi Miguel Figliozzi Jim Pankow Wentai Luo
  2. 2. Health Effects of Bicycling • Health impact studies for walking & biking have shown that physical activity benefits outweigh crash & air pollution risks by an order of magnitude or more • Still, we can & should reduce pollution risks 2Urban Bicyclists' Pollution Uptake
  3. 3. Framework 3 Vehicle Emissions Air Quality Traveler Exposure Inhalation Uptake Health Effects Bicyclists' Pollution Uptake
  4. 4. Outline 1. Exposure concentrations 2. Ventilation & inhalation dose 3. Pollutant uptake 4. Applications for transportation planning and design 4Bicyclists' Pollution Uptake
  5. 5. Bicyclist Exposure Concentrations 5Urban Bicyclists' Pollution Uptake Traveler Exposure
  6. 6. Bicyclists’ Exposures 6 0 5 10 15 20 Ultrafine PM Fine PM Coarse PM Black Carbon CO VOC NO2 # studies measuring on-road bicyclists’ exposure concentrations Pollutant 42 studies Bicyclists' Pollution Uptake 9k – 94k pt/cc 0.5 – 13 ppm 5 – 88 µg/m3
  7. 7. Modal Comparisons of Exposure – Is this actionable information? Context-dependent results – Bicyclists lower if separated 7Bicyclists' Pollution Uptake vsvs
  8. 8. High-Traffic/Low-Traffic Routes 8Bicyclists' Pollution Uptake -50% 0% 50% 100% 150% 200% 250% CO VOC UFP PM2.5 PM10 BC ExposureIncreaseon High-TrafficRoutes N=6 N=11 N=8 N=6 N=3 N=5
  9. 9. PSU Bike Exposure Research 9Urban Bicyclists' Pollution Uptake How can we reduce exposure risks for bicyclists?
  10. 10. Sampling Equipment 10Bicyclists' Pollution Uptake
  11. 11. 11 Exposure Data coverage Urban Bicyclists' Pollution Uptake
  12. 12. Results: VOC Exposure Models • +2% per 1,000 ADT • +20-30% in stop-and-go riding • Off-street path +300% in industrial corridor 12Bicyclists' Pollution Uptake
  13. 13. 13 Parallel Path Comparison Bicyclists' Pollution Uptake E Burnside St. SE Ankeney St. N Williams Ave. NE Rodney Ave. Naito Pkwy. Riverside Path
  14. 14. Bicyclist Pollution Inhalation 14Urban Bicyclists' Pollution Uptake Inhalation
  15. 15. Ventilation and Exercise 15Bicyclists' Pollution Uptake 50 100 150 200 250 Watts Ventilation(liter/min) 75 50 25 Ventilation is strongly related to exertion level
  16. 16. Ventilation & Bicycle Studies 16 57 studies assess bicyclists’ exposure Ignored 38 Constant 16 Assumed/ Modeled 15 Measured 1 Variable 3 Modeled 2 Measured 1 Ventilation: Urban Bicyclists' Pollution Uptake
  17. 17. Bicyclist Ventilation 17Urban Bicyclists' Pollution Uptake 0 1 2 3 4 5 0 5 10 15 20 RatioofBicycle/Motorized TravelerVentilation Bicycle Speed (mph) All Men Women
  18. 18. Modal Comparisons of Dose 18Urban Bicyclists' Pollution Uptake -100% -80% -60% -40% -20% 0% 20% 40% 60% Pedestrian Car/Taxi Bus DifferencefromBicyclistDose CO UFP PM2.5 N (3) (3) (5)
  19. 19. PSU Research Findings • 4-8% increase in ventilation per 10 W • Mean lag ~50 sec • Highly variable on-road 19Bicyclists' Pollution Uptake 0 50 100 150 0.0 0.2 0.4 0.6 0.8 Seconds workload lagged Cumulativeimpactonventilation(% Subjec A B C Pooled %ΔventilationperW Seconds lag
  20. 20. Bicyclist Pollution Uptake 20Urban Bicyclists' Pollution Uptake Uptake
  21. 21. Bicyclist Uptake Studies 2 studies of biomarkers: • VOC: blood & urine – Urban bikers > rural bikers • BC: induced sputum – Bicyclists > transit riders 21Bicyclists' Pollution Uptake
  22. 22. Breath Biomarkers Exhaled breath is a good proxy for blood concentrations of VOC 22Bicyclists' Pollution Uptake alphaszenszor.com VOC in blood
  23. 23. 1) Local roads Pre Breath Post Breath PSU On-Road Sampling 20-30 minutes, 3-5 miles Exposure & breath VOC Paired subjects 23Bicyclists' Pollution Uptake Pre Breath Post Breath 2) Major arterials
  24. 24. Breath and Exposure Concentrations 0 1 2 3 Breath Exposure Concentration (normalized to Park) Toluene Major arterials Local streets 24Bicyclists' Pollution Uptake
  25. 25. Breath Sampling Results • The breath sampling method works – Exposure predicts breath concentrations – Δ Breath ~ ½ Δ Exposure • 10-60% higher on major arterials than local streets – Traffic impact (over BG) 3-5x greater on major arterials than local streets 25Urban Bicyclists' Pollution Uptake
  26. 26. Explained variance in breath BTEX 26Bicyclists' Pollution Uptake 0% 10% 20% 30% 40% 50% Measured variables Modeled variables Exposure Ventilation Exposure variability Weather variables Road & traffic variables
  27. 27. Exercise and Uptake • Ventilation/inhalation rate: 2-5x higher • PM uptake: ≥2-5x higher • VOC uptake: 1.5-2x higher 27Bicyclists' Pollution Uptake
  28. 28. Applications 28Bicyclists' Pollution Uptake
  29. 29. Route Choice • Detour to reduce inhalation dose if: – <46% longer than minor arterial route – <123% longer than major arterial route • Inhalation doses +20-30% per 1% grade 29Bicyclists' Pollution Uptake ?
  30. 30. Comparison with Preferences 30Bicyclists' Pollution Uptake Will bicyclists naturally minimize inhaled dose over a trip? Bike boulevard or neighborhood greenway Bike lane Minor arterial (no bike lane) Major arterial (no bike lane) • Slightly over-avoid • Balance on collectors (6-10k ADT) • Under-avoid arterials • Greatly over-avoid vs. vs. vs.
  31. 31. Inhalation and Stops 31Urban Bicyclists' Pollution Uptake 0 100 200 300 400 500 600 6 8 10 12 14 16 18 Cruise-equivalentexcess ventilation(ft) Cruise speed (mph)
  32. 32. Inhalation and Speed 32Bicyclists' Pollution Uptake 0 50 100 150 200 250 300 0 4 8 12 16 Ventilation(l/km) Speed (mph) 0% Grade 2% Grade
  33. 33. Bikeway Design Considerations Bike lane • Higher-traffic streets • Some lateral separation • Dedicated lane reduces stops in congestion Cycle track • Higher-traffic streets • More lateral separation Bike boulevard • Low-traffic streets • Additional benefits from traffic calming • Fewer stops reduces doses Off-street path • Low exposure (nearby industry?) • Fewer stops reduces doses 33Bicyclists' Pollution Uptake
  34. 34. Take-Away Principles 1. Bicyclist Exposure a) Many different pollutants b) Traffic, weather, and land-use all important c) Benefits of separation from traffic 2. Bicyclist Inhalation a) Varies greatly with workload (speed, grade) b) Breath response spread out over 1-2 min 3. Bicyclist Uptake a) For particles, highly sensitive to breathing b) For some gases, more sensitive to exposure & duration 34Bicyclists' Pollution Uptake
  35. 35. Future Work • Abstraction for HIA & CBA • Characterizations of urban bicyclists • Similar study for pedestrians • Crowd-source pollution data 35Bicyclists' Pollution Uptake
  36. 36. Questions? abigazzi@pdx.edu alexbigazzi.com 36Bicyclists' Pollution Uptake Acknowledgments • Miguel Figliozzi, Jim Pankow, Wentai Luo • NITC, City of Portland, Portland Metro, NSF, OTREC
  37. 37. 37 Industrial Corridor Bicyclists' Pollution Uptake
  38. 38. Steady-state biking work 38Bicyclists' Pollution Uptake 0 50 100 150 200 250 0 2 3 5 6 8 9 11 13 14 16 Workload(W) Speed (mph) Rolling Resistance Drag 1% Grade
  39. 39. Minimum-Inhalation Speed 39Bicyclists' Pollution Uptake 0 5 10 15 0% 2% 4% 6% 8% 10% Minimum-ventilation speed(mph) Grade

×