Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
108 However, facilitators were free to deviate from these pre-established discussion points and questions. Each workgroup was also assigned a research team member who acted as the scribe taking notes on the discussion. 6.2 WORKSHOP FINDINGS Feedback from the workshop was plentiful and useful. The following major feedback themes significantly impacted Guidebook development: ï· There is little guidance on procuring sustainability in highway construction. Seventeen comments addressed various forms of procurement or project delivery practices. This may be a result of there being no generally recognized approach to procure sustainability in highway construction. A few contract examples were cited (Presidio Parkway, SH 130 in Texas, I-5 Willamette River Bridge, Sellwood Bridge, Oregon DOT (ODOT) bridge delivery), however these seem to be one-off and not systematic efforts. ï· Currently in construction, sustainability is not as important as cost or schedule. Nine comments addressed emphasizing sustainability through organizational support, holding pre-construction meetings, creating tracking plans, and providing feedback on sustainability efforts after construction. This may be because construction projects do not value sustainability as much as cost and schedule. As a result, sustainability goals and features may not be tracked or may be ignored/eliminated in favor of cost or schedule goals. ï· Isolating construction from other highway sustainability contributors is difficult. Several comments addressed planning and design elements that we believe to be outside the scope of this project. This may be because it is difficult to isolate the contribution of a single transportation system component (construction) to sustainability without addressing other system component (e.g., planning, design, maintenance, operation, salvage) contributions. ï· A programmatic approach may be better than one-off attempts. One series of comments advocated for a programmatic approach to sustainable materials procurement rather than a project-by-project approach. While we have not found documented research in this area, this may well be a more economical and lasting approach to integrating sustainability into materials procurement. 7 SCP RATING SURVEY After the initial compilation of the SCPs (TABLE 27) a survey was administered to the NCHRP panel, workshop invitees and participants, and the research team to assess the effort and impact of each SCP. There were 21 participants that offered a total of 3,476 responses. The goal of the SCP rating survey was to quantify the following sustainability aspects of each SCP: ï· Effort. A combined rating that represents the cost and time the respondent believes it takes to do or implement this sustainable practice.
109 ï· Human welfare. The impact the respondent believes the sustainable practice has on human health and wellbeing. How much it directly benefits people in terms of basic needs (food/water/sanitation), health and happiness (health, safety, culture, aesthetics), and personal/social development (education, equality, good governance). ï· Environmental benefit. The positive impact the respondent believes the sustainable practice has on the environment. How much it contributes to clean air/water/land, natural resources (ecological resources, water resources, and reduced consumption of these things), and climate/energy (contribution to renewable energy, reduced fossil fuel use, and GHG emissions reduction). ï· Cost savings. The immediate and long-term cost savings the respondent believes accrues from the sustainable practice. Some things may cost more up front and provide savings in the long term, and some things may seem to cost money, but may actually save money if you consider all impacts over the long term. Rating values. Each rating is done on a scale of 0-5 with the following rough meaning: 0 = no meaningful impact in this category 1 = impact is less than 1% of the total impact in this category for the project 2 = impact is 1-5% of the total impact in this category for the project 3 = impact is 5-10% of the total impact in this category for the project 4 = impact is 10-15% of the total impact in this category for the project 5 = impact is over 15% of the total impact in this category for the project Impact/effort ratio. A summary statistic called âimpact-to-effort ratioâ was calculated for each SCP by adding up the three impact category scores and dividing by the effort score. This created a single metric by which SCPs can be measured. impact-to-effort ratio human welfare environmental benefit cost savingseffort 7.1 PRECAUTIONS WHEN INTERPRETING SCP RATINGS All ratings are relative. Effort and impacts for most SCPs vary based on project context. For instance, balanced earthwork may have a large impact on an earthwork-intensive project but may have little impact on a pavement overlay. It is nearly impossible to rate a SCP for all possible contexts. Therefore, experts rated SCPs based on their own personal experience and knowledge, which varies between experts. How to use the ratings. Ratings represent a general perception of the SCP, which may or may not coincide with reality for a given context. Use these ratings as a quick guide to their effort and impacts but be comfortable with overriding them for a given projectâs context. For example, semi-permanent high-mast lighting is listed at a 2.5 for effort, but a particular project may have geometric constraints and neighborhood concerns that might make it more appropriate to consider effort a 4 or 5. Rating perceptions may not be generalizable to broad industry perceptions. Ratings by a select group of industry professionals may not be representative of the industry as a whole. This
110 is true of any population sample. Raters were selected based on their expertise in highway construction and their knowledge of sustainability as it is defined in this research; both essential to produce ratings consistent with the ideas presented in this Guidebook. Raters were not selected based on their ability to replicate industry perception. There is no absolute truth in sustainability ratings. Sustainability is context sensitive and multi-faceted; traits which effectively prohibit a universal metric based on physically measurable parameters. Therefore, sustainability ratings and accounting standards necessarily involve subjectivity. 7.2 KEY FINDINGS Summary statics are presented in TABLE 20. TABLE 20. Rating Survey Descriptive Data Descriptor Data Participants by category Public owner Construction firm / Trade association / Materials supplier Design Firm / consultant Researcher/Academia/Nonprofit 21 6 4 9 6 Average (Standard Deviation of) Scores by Category Effort Human Welfare Environmental Benefit Cost Savings OVERALL 2.294 (0.769) 2.166 (2.130) 1.890 (1.017) 1.807 (0.757) 2.039 (0.826) Number of response for a single SCP category Average Minimum Maximum 11.43 6 15 TABLE 21 through TABLE 25 list the highest and lowest scoring SCPs for each rating category and for the impact/effort ratio. FIGURE 29 and FIGURE 30 summarize results. After the SCP rating survey was complete the final editing of SCPs produced TABLE 28. The SCPs that were introduced in TABLE 28 were not rated.
111 TABLE 21. Top/Bottom 10 SCPs for Human Welfare Top 10 SCPs Score Bottom 10 SCPs Score 1. Contractor communications 3.8 67. Asphalt: density 1.1 2. Public outreach 3.7 68. Ground improvement instead of remove/replace 1.0 3. Suicide prevention programs 3.6 69. Asphalt: eliminate density differentials 1.0 4. Accelerated bridge construction (ABC) 3.6 70. Asphalt: tack coat application 0.9 5. Use a sustainability rating system 3.5 71. Concrete: HIPERPAV to predict early age behavior 0.9 6. Driver information systems 3.4 72. Paver automated grade control 0.9 7. Backup alarm modifications and alternatives 3.4 73. Geomatics 0.9 8. Work zone intrusion alerting systems (WZIA) technology 3.3 74. Concrete: dowel bar alignment 0.8 9. Work zone glare reduction 3.3 75. IDIQ contract 0.5 10. Semi-permanent high-mast lighting 3.2 76. Model-based estimation 0.5 TABLE 22. Top/Bottom 10 SCPs for Environmental Benefit Top 10 SCPs Ratio Bottom 10 SCPs Ratio 1. Use of recycled and supplementary materials 4.15 67. Contractor communications 0.8 2. Paving: on-site recycling/reuse 3.9 68. Merge control 0.7 3. Use a sustainability rating system 3.6 69. Construction vehicle entering/exiting 0.6 4. Adaptive reuse 3.5 70. Construction site aesthetics 0.6 5. Include sustainability in best value procurement 3.5 71. IDIQ contract 0.5 6. Limit site disturbance 3.4 72. Oversized load detection technology 0.5 7. Innovative use of materials in construction 3.4 73. Automated flagger assistance devices (AFAD) 0.2 8. Early inclusion of sustainability objectives 3.3 74. Work zone intrusion alerting systems (WZIA) 0.2 9. Trenchless technologies 3.3 75. Suicide prevention programs 0.1 10. Concrete: non-potable water for concrete & wash water 3.2 76. Increasing employment opportunities 0.0
112 TABLE 23. Top/Bottom 10 SCPs for Cost Savings Top 10 SCPs Ratio Bottom 10 SCPs Ratio 1. Life-cycle cost analysis (LCCA) 3.5 67. Work zone glare reduction 1.0 2. Delivery methods that allow contractor input in design 3.4 68. Tier 4 engines 1.0 3. Balanced cut/fill 3.4 69. Suicide prevention programs 1.0 4. Constructability reviews for projects 3.3 70. Alternative fuels 0.9 5. Value engineering during construction 3.1 71. EPDS included in contracts 0.7 6. Pavement on-site recycling/reuse 3.1 72. Noise reduction based on ecological impact 0.7 7. Model-based estimation 3.0 73. Use computer models to predict construction noise 0.6 8. Geo-synthetic reinforced soil- integrated bridge systems 3.0 74. Reduce noise 0.6 9. Public private partnership 2.8 75. EPDs used for materials 0.4 10. Use of recycled and supplementary materials 2.8 76. Increasing employment opportunities 0.2 TABLE 24. Top/Bottom 10 SCPs for Effort Top 10 SCPs Ratio Bottom 10 SCPs Ratio 1. Public private partnership 3.6 67. Schedule flexibility for contractor 1.8 2. Accelerated bridge construction (ABC) 3.5 68. Automated flagger assistance devices (AFAD) 1.7 3. Deconstruction 3.2 69. Asphalt: tack coat application 1.6 4. Life-cycle cost analysis (LCCA) 3.1 70. Oversized load detection technology 1.6 5. Adaptive reuse 3.1 71. Allow daytime work 1.5 6. Value engineering during procurement 3.1 72. Accelerated construction techniques 1.5 7. Life cycle cost consideration 3.0 73. Reduce noise 1.5 8. Context-sensitive rock slopes 3.0 74. Concrete: non-potable water for concrete & wash water 1.5 9. Segmental concrete 3.0 75. Anti-Idling Policy 1.3 10. Alternative fuels 3.0 76. Concrete: Dowel Alignment 1.3
113 TABLE 25. Top/Bottom 10 SCPs for Impact/Effort Ratio Top 10 SCPs Ratio Bottom 10 SCPs Ratio 1. Vehicle idling policy 5.8 67. Sust. const. safety and health rating system (SCSH) 1.8 2. Early inclusion of sustainability objectives 4.5 68. Enhanced information technologies 1.8 3. Non-potable water for concrete mixture & wash water 4.5 69. Public private partnerships 1.8 4. Use of recycled and supplementary materials 4.3 70. Context-sensitive rock slopes 1.7 5. Include sustainability in best value procurement 4.1 71. Pavement warranties 1.7 6. On-site recycling/reuse 3.8 72. Use computer models to predict construction noise 1.6 7. Sustainable procurement rules 3.8 73. Model-based estimation 1.4 8. Balance cut/fill 3.7 74. Geomatics 1.4 9. Schedule flexibility for contractor 3.6 75. Increasing employment opportunities 1.1 10. Reduce noise 3.5 76. IDIQ contract 0.9
114 FIGURE 29. Graphical representation of rating survey results in order of largest impact/effort ratio SCP (top left) to smallest impact/effort ration SCP (bottom right). Width of each bar is proportional to the total impact (human + environment + cost savings) of that SCP, height is proportional to impact/effort ratio. Key is in FIGURE 30.
115 FIGURE 30. Key for FIGURE 29.
