Portland State University PDXScholar TREC Webinar Series Transportation Research and Education Center (TREC) 4-23-2015 Webinar: Impacts of Roadway and Traffic Characteristics on Air Pollution Risks for Bicyclists Alexander Y. Bigazzi Portland State University, abigazzi@gmail.com Let us know how access to this document benefits you. Follow this and additional works at: http://pdxscholar.library.pdx.edu/trec_webinar 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. 3. http://pdxscholar.library.pdx.edu/trec_webinar/3 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 pdxscholar@pdx.edu.
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
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
Framework Vehicle Emissions Air Quality Inhalation Traveler Exposure Uptake Health Effects 3
Outline 1. Exposure concentrations 2. Ventilation & inhalation dose 3. Pollutant uptake 4. Applications for transportation planning and design 4
Traveler Exposure Bicyclist Exposure Concentrations Urban 5
Bicyclists Exposures Pollutant 42 studies NO2 VOC CO Black Carbon Coarse PM 0.5 13 ppm 5 88 µg/m 3 Fine PM Ultrafine PM 0 5 10 15 20 # studies measuring on-road bicyclists exposure concentrations 9k 94k pt/cc 6
Modal Comparisons of Exposure vs vs Is this actionable information? Context-dependent results Bicyclists lower if separated 7
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
PSU Bike Exposure Research How can we reduce exposure risks for bicyclists? Urban 9
Sampling Equipment 10
Exposure Data coverage Urban 11
Results: VOC Exposure Models +2% per 1,000 ADT +20-30% in stop-and-go riding Off-street path +300% in industrial corridor 12
Parallel Path Comparison E Burnside St. SE Ankeney St. N Williams Ave. NE Rodney Ave. Naito Pkwy. Riverside Path 13
Inhalation Bicyclist Pollution Inhalation Urban 14
Ventilation and Exercise Ventilation (liter/min) 75 50 25 Ventilation is strongly related to exertion level 50 100 150 200 250 Watts 15
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
Bicyclist Ventilation Ratio of Bicycle/Motorized Traveler Ventilation 5 4 3 2 1 0 All Men Women 0 5 10 15 20 Bicycle Speed (mph) Urban 17
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
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 0.8 0.6 0.4 0.2 0.0 Subjec A B C Pooled 0 50 100 150 Seconds lag Seconds workload lagged 19
Bicyclist Pollution Uptake Uptake Urban 20
Bicyclist Uptake Studies 2 studies of biomarkers: VOC: blood & urine Urban bikers > rural bikers BC: induced sputum Bicyclists > transit riders 21
Breath Biomarkers Exhaled breath is a good proxy for blood concentrations of VOC VOC in blood alphaszenszor.com 22
PSU On-Road Sampling Post Breath 1) 2) Local Major roads arterials Pre Breath Pre Breath Post Breath 20-30 minutes, 3-5 miles Exposure & breath VOC Paired subjects 23
Breath and Exposure Concentrations Toluene Exposure Breath Major arterials Local streets 0 1 2 3 Concentration (normalized to Park) 24
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
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
Exercise and Uptake Ventilation/inhalation rate: 2-5x higher PM uptake: 2-5x higher VOC uptake: 1.5-2x higher 27
Applications 28
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 29
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
Inhalation and Stops 600 Cruise-equivalent excess ventilation (ft) 500 400 300 200 100 0 6 8 10 12 14 16 18 Cruise speed (mph) Urban 31
Inhalation and Speed Ventilation (l/km) 300 250 200 150 100 50 0 0% Grade 2% Grade 0 4 8 12 16 Speed (mph) 32
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
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
Future Work Abstraction for HIA & CBA Characterizations of urban bicyclists Similar study for pedestrians Crowd-source pollution data 35
Questions? abigazzi@pdx.edu alexbigazzi.com Acknowledgments Miguel Figliozzi, Jim Pankow, Wentai Luo NITC, City of Portland, Portland Metro, NSF, OTREC 36
Industrial Corridor 37
Steady-state biking work 250 Rolling Resistance Drag 1% Grade 200 Workload (W) 150 100 50 0 0 2 3 5 6 8 9 11 13 14 16 Speed (mph) 38
Minimum-Inhalation Speed Minimum-ventilation speed (mph) 15 10 5 0 0% 2% 4% 6% 8% 10% Grade 39