sustainable roadways Steve Muench University of Washington

Transcription

1 sustainable roadways Steve Muench University of Washington 1

2 What we mean by sustainability

3 There are a lot of definitions for sustainable out there. Most are incomplete. This is what we think sustainability means. Sustainability is a system characteristic which refers to the system s capacity to support natural laws and human values. 3

4 There are a lot of definitions for sustainable out there. Most are incomplete. This is what we think sustainability means. Sustainability is a system characteristic which refers to the system s capacity to support natural laws and human values. Natural laws = Ecology Rule: Don t break the earth How we do this: 1. Do not take stuff out of the earth faster than it will go back in. 2. Do not produce stuff (e.g., pollution) faster than it can be broken down and integrated back into nature. 3. Do not diminish nature s productivity or diversity or we will affect nature s ability to process stuff that we create or use. 4

5 There are a lot of definitions for sustainable out there. Most are incomplete. This is what we think sustainability means. Sustainability is a system characteristic which refers to the system s capacity to support natural laws and human values. Natural laws = Ecology Rule: Don t break the earth Human values = equity and economy Equity rule: Seek quality of life for all Economy rule: Manage resources wisely Resources = human, natural, manufactured and financial capital 5

6 There are a lot of definitions for sustainable out there. Most are incomplete. This is what we think sustainability means. Sustainability is a system characteristic which refers to the system s capacity to support natural laws and human values. Sustainability can be: Measured Judged Managed Improved 6

7 There are a lot of definitions for sustainable out there. Most are incomplete. This is what we think sustainability means. Sustainability is a system characteristic which refers to the system s capacity to support natural laws and human values. Humanity has the ability to make development sustainable to ensure that it meets the needs of the present without compromisingthe ability of future generations to meet their own needs. UN World Commission on Environment and Development (WECD) Report (1987) chaired by Gro Harlem Brundtland (Norway s prime minister then) on page 24 7

8 Sustainability does not make much sense unless you also include 4 more items. Defining sustainable for your project Extent: how long do you want it to last? Expectations: What are the performance expectations? Making sustainability work Experience: Need technical expertise to develop solutions Exposure: Education and public awareness 8 7 total components: ecology, equity, economic extent, expectations, experience, exposure

9 We are really just talking about being more sustainable than we were. We are going for do less bad. The goal is do good. Bad Break Even Point Good Use > replace Produce > broken down Excess = damage Change nature Use = replace Produce = broken down Excess = benefit Integrated into nature humans ants cherry trees 9 Example drawn from ideas in McDonough and Braungart s Cradle to Cradle (2002)

10 So what does a more sustainable roadway look like?

11 warm mix asphalt life cycle cost analysis env. mgmt. sys. long lasting l pavement scenic views local material natural cut slope recycled materials LID stormwater 11 quality construction

12 less paving emissions env. mgmt. sys. recycled materials art long lasting pavement pedestrian access local material scenic views LID stormwater 12 quality construction

13 The Greenroads rating system.

14 Sasobit Warm Mix Asphalt I 90 near George, WA 23 June 2008 What is it? Greenroads is a rating system designed to distinguish more sustainable new or redesigned/rehabilitated roads. It awards points for approved sustainable choices/practices and can be used to certify projects based onpoint value. How does it help? More sustainable roadways. This means less impact on the environment, lower life cycle costs/impacts and better quality of life.

15 Quiet Pavement SR 520 Near Bellevue, WA 14 July 2007 Greenroads is a project oriented oriented system. It does not deal with planning and it does not deal with operations. Planning Design & Construction ti Operation

16 Greenroads Categories Category Description points Project Requirements Minimum requirements for a Greenroad 11 Environment & Water Stormwater, habitat, vegetation 14 Access & Equity Modal access, culture, aesthetics, safety 14 Construction Activities Construction equipment, quality, use 15 Materials & Resources Material extraction, processing, transport 12 Pavement Technology Pavement design, material use, function 11 Custom Credits Write your own credit for approval 10 Total 76 16

17 Project Requirements (PR) Description NEPA Compliance Req Pavement preservation plan Req Environmental Maintenance Plan Req LID Stormwater Treatment Techniques Req Educational Outreach Req Construction Quality Control Req C&D Waste Management Plan Req Life Cycle Cost Analysis Req Life Cycle Inventory Req Stormwater Pollution Prevention Plan (SWPPP) Req Noise Mitigation Plan Req Total Requirements 11

18 18 Sustainability says we should consider the environment in roadway project decisions.

19 One helpful tool is a life cycle assessment (LCA). LCA can provide quantities A protocol to assess the environmental, economic, and social impacts of an industrial system. The life cycle of the industrial system extends from cradle to grave: from materials acquisition and production, through manufacturing, system use and maintenance, and finally through the end of the system s life. 19

20 transport refinery transport oil extraction other inputs Aggregate Quarry transport hma plant water fuel other outputs placement transport emissions waste hazardous waste An example of LCA processes, inputs and outputs to consider for HMA paving.

21 For a given unit of production (e.g., 1 lane-mile of pavement) a typical LCA gives a range of outputs. Amount of materials used (tonnes) Total energy use (MJ) Water consumption (kg) Emissions Global warming potential (tonnes of CO 2 equivalent) Nitrogen oxides NO x (kg) Sulfur dioxide SO 2 (kg) Particulate matter PM 10 (kg) Carbon Monoxide CO(kg) Toxic things Humantoxicity potential Mercury Hg(g) Lead Pb(g) Hazardous waste (kg) (g)

22 Example PR Requirement Life Cycle Inventory REQ Use an existing approved software toolto conduct a life cycle inventory (LCI) of the pavement structure as a minimum. Other project features maybe included but are not required. Currently, a simplified LCA of an entire project is not possible because there are no capable tools. A detailed LCA is given credit in MR and would likely require a specialized consultant to complete. Even the standard pavement LCA tool, PaLATE has serious shortcomings that render its current results questionable at best. 22

23 Example LCA Output from PaLATE: 1lanemile lane-mile of HMA overlay in Seattle 1.8 inch mill and inlay of existing road using HMA (20% RAP) City of Seattle, Summer 2008 Material Quantities for 1 lane mile (12 ft wide lane) Rock Products 236 yd 3 Asphalt 35 yd 3 RAP 63 yd 3 = 20% of total 23 Energy, Water and Emissions for 1 lane mile (12 ft wide lane) Energy TJ = 12 US households in 1 year Water 28 kg = 1 US household for 1 day CO 2 9 Mg = 1 US households in 1year NO x 225 kg PM kg Based on PaLATE v2 as altered by UW in December 2008

24 Materials & Resources (MR) Description points Life Cycle Assessment: Enhanced 2 Native Soil Rehabilitation 1 Pavement Reuse 2 Recycled Content 1 4 Regionally Provided Material 1 2 Energy Efficiency 1 Total Points Available 12

25 We have done well recycling hot mix asphalt and portland cement concrete as part of road construction. Waste in Washington State 18 Asphalt and Concrete Recycled 1999 to Landfilled Other Diverted Waste Diverted HMA and PCC Millions of Tons HMA/PCC recycling = 30% of diverted waste Graph from Washington State Department of Ecology data Year 30% of diverted waste

26 We can do better. We can reduce the amount to landfills, and increase the amount to high-value surfacings. Destination of Recovered HMA Destination of Recovered PCC Landfill 20% Landfill 20% HMA 27% Base Material 53% Fill, Rip-Rap and Other 14% Base Material 54% HMA/PCC 12% 26 Data from the USGS

27 Example MR Credit Recycled Content 1 4 points One point: Use recycled content to a minimum of 20% in the HMA/PCC and 40% of the total material if base course, fill, or structures t are included din the project. Two points: Use recycled content to a minimum of 30% in the HMA/PCC and 50% of the total material if base course, fill, or structures are included in the project. Three points: Use recycled content to a minimum of 40% in the HMA/PCC and 60% of the total material if base course, fill, or structures are included in the project. 27 Four points: Use recycled content to a minimum of 50% in the HMA/PCC and 70% of the total material if base course, fill, or structures are included in the project.

28 But there is always something that standard methods miss. Lafarge Materials in Seattle (2008) Recycled Material Material Percentage Type 1 Cement 32.8% GGBFS 95.0% MaxCem (80% Type % GGBFS) 45.2% 28 Ground granulated blast furnace slag at Lafarge in West Seattle.

29 Certification Levels Version 0.96: 76 Total Points points points points 47+ points 30-40% 40-50% 50-60% 60+% of total of total of total of total 29

30 Incorporating context into Greenroads

31 Greenroads credits can be mapped to the elements of sustainability and fundamental resources. Elements of Sustainability Ecology Equity Economy Extent Expectations Expertise Exposure Air Water Earth Virgin space Developed space Non human life Human life Renewable energy Non renewable energy 31

32 Greenroads Rating System Sustainability Footprint 100% 90% 80% Ecology Experience 70% 60% 50% 40% 30% 20% 10% 0% Equity Exposure Economy Expectations Extent Where noted, PR and/orep is excluded. PR 5, PR 6, PR 7 weighted as equalto2 credits for comporative weighting purposes. 32 All Credits & Requirements

33 Greenroads Rating System Mapped to Sustainability* No. of Cred dits Ecology Equity Economy Extent Expectations Exposure Experience Sustainability Component *PR Category Included. PR 5, 33PR 6, PR 7 weighted as equal to 2 credits for comporativeweighting purposes.

34 Why bother?

35 Why bother with a rating standard? More sustainable roads Specific benefits: Defines basic roadway sustainability attributes Greater participation ii i in roadway sustainability Better evaluation of tradeoffs and decisions Providemeansfor sustainability assessment Allows innovation because it is end result oriented Confer marketable recognition on projects 35

36 What makes a roadway more or less sustainable and how do you translate these qualities into actionable items? Researched and backed with empirical evidence Weighted based on impact Each item is directly actionable on a project level Each item referenced to sustainability components A Convenient List 36

37 If improving sustainability is an agency/company goal, how do you assess your performance? Some examples from LEED: City of Seattle: Sustainable Building Policy All City construction projects over 5,000 ft 2 must meet LEED Silver rating level. LEED Pilot program provides small grants to help. King County Highest LEED level achievable based on life cycle cost analysis and funding. Applies to all new construction and renovation over $250,000. Washington State All State funded projects over 5,000 ft 2 have a goal of LEED silver. 37 Note: In FY 2008 WSDOT awarded 149 highway construction and ferry terminal contracts. They are generally not covered by the WSDOT LEED criteria.

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39 We need to be on the map. Construction Market Design Market 39 Source: ENR (24 Sep 2007) The Mainstreaming of Green Building (Tulacz) Source: ENR (18 May 2008) No Longer a Fad, Green Hits Mainstream (Tulacz and Traynor)

40 Greenroads effort right now (11 April 2009) Who is developing Greenroads? University of Washington and CH2M HILL Who is funding Greenroads so far? TransNow (DOT Region 10 University Transportation Center) State Pavement Technology Consortium (WA, CA, MN, TX) Federal Lands Highway Division (FLHD) What is the status right now? Version 0.95 now Online: When can it be used? We want comments and pilot projects NOW Let us know via the website ( 40

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42 Sustainability is the next great game in transportation. The game becomes serious when you keep score. Greenroads keeps score.