TABLE 1 Literature Review Matrix No. Study Choice Context Study Area Pollutants Considered (Units) Method of Analysis Shortest Routes Exposure 1. Hankey et al. (2017) Bicycle and pedestrian streets and trails Minneapolis, USA PM2.5 , BC --- Land use regression (LUR) model 2. Good et al. (2016) Bicycle route Fort Collins, USA BC, PM2.5 , PNC (#/cm3), CO (ppm) Manually selected routes measurement 3. Molter and Lindley (2015) Walking routes of primary school children Manchester, UK NO2 , PM10 Simulation Land use regression (LUR) model 4. Davies and Hyatt (2014) Walking route of pedestrians Lancaster, UK PM2.5 ArcGIS network analysis Dispersion modeling 5. Sharker and Karimi (2014) Road network routes Pittsburgh, USA O3 (ppb) --- EPA data 6. Hatzopoulou et al. (2013) Bicycle route Montreal, Canada NO2 (ppb) ArcGIS network analysis based on real life origins and destinations Land use regression (LUR) model 7. Jarjour et al. (2013) Bicycle route Berkeley, California PM2.5 , CO (ppm), BC Manually selected routes Actual measurement 8. Cole-Hunter et al. (2013) Bicycle route Queensland, Australia PNC (ppcc) Manually selected routes Actual measurement 9. Su et al. (2010) Bicycle route Vancouver, Canada NO2 (ppb) Google map interface Land use regression (LUR) 10. Hertel et al. (2008) Bicycle and transit route Copenhagen, Denmark NOx, CO, NO2, PM10, PM2.5 ArcGIS network analysis Street pollution model
TABLE 2 Attribute Levels for the SP Experiments Attribute Category Attribute Definition of Attribute Attribute Levels Roadway characteristics Grade Nature of terrain Flat Moderate Steep Traffic volume Amount of traffic on the roadway Light Moderate Roadway type Functional classification of roadway Residential /Local roads Minor arterial Major arterial Bike route characteristics Cycling infrastructure continuity Continuous bike route – if the whole route has a bicycle facility (a bike lane or shared-use path) Discontinuous - otherwise Continuous Discontinuous Cycling infrastructure segregation Exclusive/Segregated – if physically separated from motor vehicle traffic Shared – otherwise Exclusive Shared Environmental condition Amount of air pollution subjected to while cycling Mean exposure levels to pollutants 5 ppb 10 ppb 15 ppb Maximum exposure levels to pollutants 20 ppb 40 ppb 60 ppb Trip characteristics Duration of trip Travel time to destination 20 minutes 25 minutes 30 minutes 35 minutes 40 minutes TABLE 3 Sample Characteristics Demographics Percentages within Sample of Respondents Gender Males: 58% Females: 42% Age 18-24 years: 19% 25-34 years: 41%
35-44 years: 20% 45-54 years: 13% 55-64 years: 6% ≥ 65 years: 1% Education High school: 10% College: 10% Bachelors: 33% Graduate or higher: 47% Employment Type Student: 30% Full-time worker: 61% Part-time worker: 7% Retired: 1% Not/self-employed: 1% Household Income ≤ $30K: 21% $30K-$45K: 8% $45K-$60K: 9% $60K-$75K: 11% $75K-$100K: 13% $100K-$150K: 20% ≥ $150K: 19% Household Size 1 person: 23% 2 persons: 36% 3 persons: 18% ≥4 persons: 22%
4 Estimation Results Attribute Category Attribute Attribute Levels Coefficient t-statistics Roadway characteristics Grade (Base: Flat) Steep -0.982 -10.579 Female -0.804 -5.601 Traffic volume (Base: Light) Moderate -0.657 -7.729 Heavy -1.508 -16.662 Roadway type (Base: Residential roads) Minor arterial -0.398 -4.776 Major arterial -1.290 -15.025 Female -0.345 -2.576 Bike route characteristics Infrastructure continuity (Base: Discontinuous) Continuous 0.879 13.485 Infrastructure segregation (Base: Shared) Exclusive 0.939 10.353 Female 0.306 2.561 Environmental condition Mean exposure Mean exposure -0.054 -8.791 Biking experience (Base: 2 or more years) Less than 2 years -0.021 -1.961 Maximum exposure Maximum exposure -0.019 -10.271 Standard deviation 0.016 6.480 Exposure impact information (Base: No information) Short-term -0.007 -2.148
TABLE 5 Time based Trade-offs across Gender Attribute Attribute Levels Time (minutes) Male Female Grade 13.10 23.81 Traffic volume Moderate 8.76 8.76 Heavy 20.11 20.11 Roadway type Minor arterial 5.31 5.31 Major arterial 17.20 21.80 Infrastructure continuity Continuous 11.72 11.72 Infrastructure segregation Exclusive 12.52 16.60 Environmental condition Mean exposure (10 ppb) 7.20 7.20 Maximum exposure (40 ppb) 10.13 (-6.6/26.8) 10.13 (-6.6/26.8)