Webinar: Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclists

Transcription

1 Portland State University PDXScholar TREC Webinar Series Transportation Research and Education Center (TREC) Webinar: Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclists Alexander Y. Bigazzi Portland State University, Let us know how access to this document benefits you. Follow this and additional works at: Part of the Transportation Commons, Transportation Engineering Commons, and the Urban Studies Commons Recommended Citation Bigazzi, Alexander Y., "Webinar: Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclists" (2015). TREC Webinar Series This Book is brought to you for free and open access. It has been accepted for inclusion in TREC Webinar Series by an authorized administrator of PDXScholar. For more information, please contact

2 TREC Webinar 22 April, 2015 Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclists Miguel Figliozzi Jim Pankow Wentai Luo Alex Bigazzi

3 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 Urban 2

4 Framework Vehicle Emissions Air Quality Inhalation Traveler Exposure Uptake Health Effects 3

5 Outline 1. Exposure concentrations 2. Ventilation & inhalation dose 3. Pollutant uptake 4. Applications for transportation planning and design 4

6 Traveler Exposure Bicyclist Exposure Concentrations Urban 5

7 Bicyclists Exposures Pollutant 42 studies NO2 VOC CO Black Carbon Coarse PM ppm 5 88 µg/m 3 Fine PM Ultrafine PM # studies measuring on-road bicyclists exposure concentrations 9k 94k pt/cc 6

8 Modal Comparisons of Exposure vs vs Is this actionable information? Context-dependent results Bicyclists lower if separated 7

9 High-Traffic/Low-Traffic Routes 250% Exposure Increase on High-Traffic Routes 200% 150% 100% 50% 0% -50% N=6 N=11 N=8 N=6 N=3 N=5 CO VOC UFP PM2.5 PM10 BC 8

10 PSU Bike Exposure Research How can we reduce exposure risks for bicyclists? Urban 9

11 Sampling Equipment 10

12 Exposure Data coverage Urban 11

13 Results: VOC Exposure Models +2% per 1,000 ADT % in stop-and-go riding Off-street path +300% in industrial corridor 12

14 Parallel Path Comparison E Burnside St. SE Ankeney St. N Williams Ave. NE Rodney Ave. Naito Pkwy. Riverside Path 13

15 Inhalation Bicyclist Pollution Inhalation Urban 14

16 Ventilation and Exercise Ventilation (liter/min) Ventilation is strongly related to exertion level Watts 15

17 Ventilation & Bicycle Studies 57 studies assess bicyclists exposure Ventilation: Ignored 38 Constant 16 Variable 3 Assumed/ Modeled 15 Measured 1 Modeled 2 Measured 1 Urban 16

18 Bicyclist Ventilation Ratio of Bicycle/Motorized Traveler Ventilation All Men Women Bicycle Speed (mph) Urban 17

19 Modal Comparisons of Dose 60% Difference from Bicyclist Dose 40% 20% 0% -20% -40% -60% -80% -100% Pedestrian Car/Taxi Bus CO UFP PM2.5 N (3) (3) (5) Urban 18

20 PSU Research Findings 4-8% increase in ventilation per 10 W Mean lag ~50 sec Highly variable on-road Cumulative impact on ventilation (% % Δ ventilation per W Subjec A B C Pooled Seconds lag Seconds workload lagged 19

21 Bicyclist Pollution Uptake Uptake Urban 20

22 Bicyclist Uptake Studies 2 studies of biomarkers: VOC: blood & urine Urban bikers > rural bikers BC: induced sputum Bicyclists > transit riders 21

23 Breath Biomarkers Exhaled breath is a good proxy for blood concentrations of VOC VOC in blood alphaszenszor.com 22

24 PSU On-Road Sampling Post Breath 1) 2) Local Major roads arterials Pre Breath Pre Breath Post Breath minutes, 3-5 miles Exposure & breath VOC Paired subjects 23

25 Breath and Exposure Concentrations Toluene Exposure Breath Major arterials Local streets Concentration (normalized to Park) 24

26 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 Urban 25

27 Explained variance in breath BTEX 50% 40% 30% Ventilation Exposure variability Weather variables 20% 10% Exposure Road & traffic variables 0% Measured variables Modeled variables 26

28 Exercise and Uptake Ventilation/inhalation rate: 2-5x higher PM uptake: 2-5x higher VOC uptake: 1.5-2x higher 27

29 Applications 28

30 Route Choice Detour to reduce inhalation dose if: <46% longer than minor arterial route <123% longer than major arterial route? Inhalation doses % per 1% grade 29

31 Comparison with Preferences Will bicyclists naturally minimize inhaled dose over a trip? vs. Bike lane Balance on collectors (6-10k ADT) Under-avoid arterials Bike boulevard or vs. Minor arterial (no bike lane) Slightly over-avoid neighborhood greenway vs. Major arterial (no bike lane) Greatly over-avoid 30

32 Inhalation and Stops 600 Cruise-equivalent excess ventilation (ft) Cruise speed (mph) Urban 31

33 Inhalation and Speed Ventilation (l/km) % Grade 2% Grade Speed (mph) 32

34 Bikeway Design Considerations Bike lane Cycle track Bike boulevard Off-street path Higher-traffic streets Some lateral separation Dedicated lane reduces stops in congestion Higher-traffic streets More lateral separation Low-traffic streets Additional benefits from traffic calming Fewer stops reduces doses Low exposure (nearby industry?) Fewer stops reduces doses 33

35 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 34

36 Future Work Abstraction for HIA & CBA Characterizations of urban bicyclists Similar study for pedestrians Crowd-source pollution data 35

37 Questions? alexbigazzi.com Acknowledgments Miguel Figliozzi, Jim Pankow, Wentai Luo NITC, City of Portland, Portland Metro, NSF, OTREC 36

38 Industrial Corridor 37

39 Steady-state biking work 250 Rolling Resistance Drag 1% Grade 200 Workload (W) Speed (mph) 38

40 Minimum-Inhalation Speed Minimum-ventilation speed (mph) % 2% 4% 6% 8% 10% Grade 39