Developing green bridge rating system using Simos’ procedure

Peer review under responsibility of Housing and Building National Research Center.

Figures & data

Table 1 Initial criteria list.

ID	Criteria	Description
Project requirements category
PR-1	Life Cycle Cost Analysis	Presenting a Life Cycle Cost (LCC) analysis of all significant bridge materials to be used in the Project.
PR-2	Cultural Heritage	Incorporating architectural, construction and technical solutions which excel in reflecting national and regional cultural heritage, while contributing to the environmental performance of the bridge.
PR-3	Noise Mitigation Plan	Strategies toward noise mitigation, as construction of noise barriers, tinning of pavement to reduce noise levels.
PR-4	Waste Management Plan	Presenting a project Waste Management Plan that includes strategies from reducing, and, where possible, re-using and recycling the waste arising from the project operations.
PR-5	Pavement Management plan	Strategies toward extended green pavement construction, life; design and rehabilitation.
PR-6	Site Maintenance Plan	Providing simple and easily-followed Operations manual bridge components.
PR-7	Potential for Innovations	Presentation of an innovative design or construction practices which have a significant measurable environmental benefit and implementation plan, and bridge reuse.
PR-8	On-site Renewable Energy	Percentage of total energy demand is supplied through renewable energy, utilizing on-site or off-site sources. An on-site and/or off-site renewable energy feasibility study has been undertaken.
PR-9	LEED Accredited Professional	At least ONE principal participant of the project team shall be a LEED Accredited Professional (AP).
Environment and water category
EW-1	Site Vegetation	Consider the use of native vegetation with no irrigation
EW-2	Habitat Restoration	Demonstrating a suitable strategy for conserving or restoring natural areas to provide habitat and promote biodiversity, including the preserving/replanting of trees found on site.
EW-3	Sustainable sites Selection	Projects that redevelop a brown field site in order to achieve maximum benefit from such areas and to rationalize land use. The site has been including an Environmental Site Assessment),
EW-4	Respect for historic sites	Demonstrating a suitable strategy for conserving and protecting remains of historic or cultural interest that is part of or nearby the site.
Access and equity category
AE-1	Intelligent Transportation Systems	Demonstrating strategies to reduce reliance on traditional transportation systems, and encourage the use of greener and intelligent methods of transport.
AE-2	Providing a Bridge User Guide	Building user guide containing the necessary technical and non-technical information for the bridge users/occupant to enable the efficient and responsible operation.
AE-3	Periodic Maintenance Schedule	The provision of a Periodic Maintenance Schedule, which should be comprehensive and regularly updated.
AE-4	Pedestrian/Bicycle Access	Consider approaches for improving conditions for bicycle and pedestrian travel within roadway improvement projects. Conditions within project corridors provide sufficient comfort and safety level in order to encourage pedestrian and bicycle movements, thereby reducing the need for driving (and accompanying energy usage) for many short distance trips.
AE-5	Transit Access	Increased use of rail transit can reduce traffic on highway bridges in the most congested areas, potentially reducing congestion, and fuel consumption. Park-and-Ride lots serve as an intermodal staging locations.
AE-6	Visual Enhancements	The project provides the traveling public an opportunity to see a scenic view either during travel or by providing a stopped observation point.
Construction activities category
CA-1	Equipment Emission Reduction	Mitigating noise and exhaust emissions from machinery and equipment on Site.
CA-2	Access Roads	Providing proper access roads for trucks to reduce any negative impact on the environment during site operations.
CA-3	Storage/Separation areas	Providing site storage areas, separation of flammable and toxic materials and prevention of soil pollution in these areas.
Materials and resources category
MR-1	Pavement Reuse	Building cost effective pavement systems by using recycle and/or reuse materials.
MR-2	Earthwork Balance	Balancing cuts and fills can reduce the need for borrow excavation, which can reduce vehicle emissions and pollution generated by the transportation of soils in and out of the project corridor
MR-3	Recycled Materials Reuse	Preserving natural resources and protecting the environment by reducing the use of natural resources and increasing the use of recycle/reuse materials
MR-4	Regional Materials	Projects with specifications that support the use of local materials depending on the location of the project, whenever practical.
MR-5	Long-Life Pavement	Specifying the use of perpetual HMA pavement with 40 or more years of design life.

Table 2 Questionnaire survey results.

ID	Criteria	Mean	Standard error
PR-1	Lifecycle Cost Analysis	7.5	0.156
PR-2	Cultural Heritage	5.0	0.152
PR-3	Noise Mitigation Plan	6.1	0.125
PR-4	Waste Management Plan	6.4	0.185
PR-5	Pavement Management plan	2.8	0.126
PR-6	Site Maintenance Plan	7.2	0.154
PR-7	Potential for Innovations	6.2	0.177
PR-8	On-site Renewable Energy	6.11	0.194
PR-9	LEED Accredited Professional	4.90	0.164
EW-1	Site Vegetation	4.81	0.153
EW-2	Habitat Restoration	6.21	0.144
EW-3	Sustainable sites Selection	6.90	0.156
EW-4	Respect for historic sites	8.18	0.111
AE-1	Intelligent Transportation Systems	6.80	0.144
AE-2	Providing a Bridge User Guide	6.26	0.149
AE-3	Periodic Maintenance Schedule	2.96	0.131
AE-4	Pedestrian/Bicycle Access	7.03	0.168
AE-5	Transit Access	6.96	0.170
AE-6	Visual Enhancements	6.19	0.145
CA-1	Equipment Emission Reduction	6.56	0.167
CA-2	Access Roads	1.37	0.059
CA-3	Storage/Separation areas	7.70	0.126
MR-1	Pavement Reuse	6.81	0.182
MR-2	Earthwork Balance	7.07	0.175
MR-3	Recycled Materials Reuse	6.96	0.187
MR-4	Regional Materials	7.74	0.132
MR-5	Long-Life Pavement	7.41	0.129

Fig. 1 Estimated mean values of importance level for the final list of criteria.

Table 3 Relative weights of criteria within categories.

Criteria	Model Rank	Position	Global Weight
PR-1	73	74	0.185
PR-3	62	62	0.156
PR-4	64	65	0.162
PR-6	72	73	0.182
PR-7	62	63	0.155
PR-8	63	64	0.159
EW-2	62	62	0.289
EW-3	70	70	0.327
EW-4	82	82	0.383
AE-1	70	72	0.211
AE-2	63	63	0.186
AE-4	70	71	0.211
AE-5	70	70	0.211
AE-6	61	61	0.181
CA-1	66	66	0.462
CA-3	77	77	0.538
MR-1	67	67	0.188
MR-2	70	70	0.196
MR-3	68	68	0.190
MR-4	77	77	0.215
MR-5	75	75	0.210

Table 4 Relative weights of categories.

Category	Weight
Project Requirements	0.189
Environment and Water	0.205
Access and Equity	0.192
Construction Activities	0.209
Materials and Resources	0.206

Table 5 Simos’ estimated weights of criteria.

ID	Criteria	Weight
PR-1	Lifecycle Cost Analysis	0.0348
PR-3	Noise Mitigation Plan	0.0294
PR-4	Waste Management Plan	0.0306
PR-5	Pavement Management plan	0.0343
PR-6	Site Maintenance Plan	0.0294
PR-7	Potential for Innovations	0.0301
PR-8	On-site Renewable Energy	0.0348
EW-2	Habitat Restoration	0.0592
EW-3	Sustainable sites Selection	0.0669
EW-4	Respect for historic sites	0.0783
AE-1	Intelligent Transportation Systems	0.0403
AE-2	Providing a Bridge User Guide	0.0358
AE-4	Pedestrian/Bicycle Access	0.0403
AE-5	Transit Access	0.0403
AE-6	Visual Enhancements	0.0346
CA-1	Equipment Emission Reduction	0.0964
CA-3	Storage/Separation areas	0.1120
MR-1	Pavement Reuse	0.0386
MR-2	Earthwork Balance	0.0403
MR-3	Recycled Materials Reuse	0.0392
MR-4	Regional Materials	0.0444
MR-5	Long-Life Pavement	0.0432

Fig. 2 Credit distribution among bridge rating system categories.

Fig. 3 Proposed bridge rating system classes.

Table 6 Proposed credits for green bridge rating system.

Criteria	Proposed credit
Project Requirements (26 Credits)
Lifecycle Cost Analysis	4
Noise Mitigation Plan	3
Waste Management Plan	4
Pavement Management plan	4
Site Maintenance Plan	3
Potential for Innovations	4
On-site Renewable Energy	4
Environment and Water (21 Credits)
Habitat Restoration	6
Sustainable sites Selection	7
Respect for historic sites	8
Access and Equity (23 Credits)
Intelligent Transportation Systems	5
Providing a Bridge User Guide	4
Pedestrian/Bicycle Access	5
Transit Access	5
Visual Enhancements	4
Construction Activities (6 Credits)
Equipment Emission Reduction	3
Storage/Separation areas	4
Materials and Resources (20 Credits)
Pavement Reuse	4
Earthwork Balance	5
Recycled Materials Reuse	4
Regional Materials	5
Long-Life Pavement	5
Total	100