“ Green ” PORTAL:

1. “Green” PORTAL: Adding Sustainability Performance Measures to a Transportation Data Archive Emissions Modeling

2. Outline • Objectives • Freeway emissions factors • Emissions models • MOBILE 6 model • PORTAL and model inputs • Emissions measures • Conclusions

3. Green PORTAL Project Objectives:

4. Motivations? • Internationally, road transport is the largest anthropogenic source of urban air pollution. • Beyond emissions, transportation is a heavy user of society’s time and energy resources.

5. Sustainability Performance Measures Using Archived ITS Data: • Emissions Estimates • Fuel Consumption • Cost of Delay • Person Mobility (PMT, PHT, PHD) (this presentation)

6. Emissions Modeling and Estimation

7. Factors Affecting Emissions

8. Emissions Estimation

9. Average Speed Emissions Models Model Development Process:

10. Some Average Speed Model Considerations • Does not fully capture speed dynamics (though facility-specific drive cycles can approximate) • Using speed distributions (as opposed to simply mean speed) can increase estimates by up to 9% • Accuracy increased with other inputs: hourly and roadway vehicle fleet, weather, facility type, fuel programs, etc. • Accuracy relies on relevance of drive cycles and tested vehicles • All emissions models have a significant level of uncertainty

11. MOBILE 6 (a robust average speed emissions model) • Created by U.S. Environmental Protection Agency • This version (6) released January 2001; MOBILE models date back to 1978 • Standard usage in North America for regulatory compliance (Clean Air Act) • Available free at: http://www.epa.gov/otaq/m6.htm • Soon to be replaced by MOVES model from EPA

12. MOBILE 6.2 Improvements and caveats • New facility-specific drive cycles recorded in modern American cities • Updated vehicles, emissions rates, regulatory programs, and driver behaviors • Fuel consumption and CO2 estimates not speed-dependent (only based on fuel and fleet data) • Non-specified parameters default to national averages (many county-specific data available from the EPA)

13. PORTAL Regional transportation data archive at PSU portal.its.pdx.edu

14. Raw Data from PORTAL 20-second count, occupancy, and speed from ~600 inductive loop detectors on the Portland metropolitan freeway system -Hourly weather data also available -Auto/truck split estimates calculated from 20-second occupancy and speed

15. Performance Measure Methodology

16. MOBILE Model Input Parameter Summary

17. Hourly CO2 Estimate I-5 MP 302.5 (1.4 mile section)

18. Volatile Organic Compounds I-5 MP 302.5 (1.4 mile section)

19. VOC Emissions From Congestions I-5 MP 302.5 (1.4 mile section)

20. CO Emissions From Congestions I-5 MP 302.5 (1.4 mile section)

21. A Quick Comparison . . . Note: There are many other factors (temperature) and sources (non-mobile) for CO in Portland. This was simply a sample visual comparison, not a correlation analysis.

22. Future Improvements

23. Conclusion • These “green” performance measures offer key transportation system sustainability indicators that can readily be calculated from existing PORTAL data. • While these measures can offer new insights, they rely on the accuracy of the archived data as well as the models. • The next step in this project will be online, automated implementation of these measures based on the methods described here.

24. THANK YOU! Questions? - Comments? Acknowledgments: Funding and support for this project is provided by the National Science Foundation, Oregon Department of Transportation, Federal Highway Administration, City of Portland, TriMet and Metro. Special thanks to the PORTAL development team, PORTAL users and the TransPort ITS committee for their feedback and support. Thank you to Dr. Robert Bertini, Portland State University Photo credits: Julie Verdini and PORTAL