Analysis and evaluation of safety impacts of median types and midblock left turn treatments for urban arterials

Urban growth leads to new land-uses abutting arterials requiring driveways for their accessibility. Uncontrolled number and locations of such access points causes safety, mobility and accessibility problems. The solution to these problems is access management (AM) which controls the number and location of the access points. AM techniques are normally documented in the form of guidelines for engineers and planners to follow when implementing the techniques. However, AM guidelines may not cover every technique due to the fact that AM is still growing. For example, the current AM guideline prepared by The Nevada Department of Transportation addresses many AM techniques. The guideline, however, addresses the design of lengths and ends of median openings but not spacing and type of the openings in segments with raised median (RM). Spacing, location, and types of median openings have impacts on safety of midblock sections of arterials. Short spacing of median openings results in overlapping functional areas and consequently high number of traffic conflicts and crashes. Long spacing of median openings results in few median openings in a given segment length hence concentrating turning traffic at those few median openings. Concentrating turning traffic at the openings increases potential conflicts, impedance to through traffic, and accessibility problems. This study evaluates the impacts of median type, density, spacing, location, and type of median openings and proposes optimal spacings that minimize number of crashes. This study deviates from past studies that evaluated safety impacts of an aggregate number of median openings using crash data collected over shorter periods of one to three years. The studies reported mixed results, making it difficult to transfer findings across geographical locations. Aggregating the impacts might have concealed the impacts of individual spacing between median openings. Statistical models were calibrated for median openings in RM segments at aggregate and disaggregate levels of analysis. Other variables such as signal spacing, number of driveways, land-use, AADT, and speed limits were included. Results of the analyses reveal that density, spacing, location and type of median openings do have significant impacts on midblock crashes. The results show that one median opening in a mile corresponds to 5.7% and 5.3% total and injury crash rates, respectively. Optimal spacing of the median openings is found in the range of 340 feet to 730 feet based on types of crashes and speed limits. Median openings located adjacent to signalized intersection have up to 30% more crashes than intermediate openings. The results of this research are expected to assist transportation agencies in prioritizing retrofit projects, updating existing, and developing new AM strategies related to spacing between median openings

Greenhouse gas emissions associated with road transport projects: current status, benchmarking, and assessment tools

Global warming and climate change have been two much-debated topics in recent times due to their malevolent consequences not only to ecosystems, but also to the human race. They are indeed negative by-products of greenhouse gas (GHG) emissions. The transportation sector is a major contributor of GHG emissions, accounting for approximately 20 percent of all carbon dioxide (co2) emissions globally, and road transportation accounts for the large majority of those emissions. This paper reviews literature related to GHG emissions produced by construction, operation, and maintenance phases of road projects. It compares country-specific GHG emission levels and provides input on assessment tools that can be used to estimate road project-specific GHG emissions. Lastly, the paper draws conclusions in regards to the magnitude of GHG emissions produced by road transportation, as well as to the status of assessment tools readily available in the market. The authors find that GHG emissions continue to be a concern, especially in the Gulf Cooperation Countries (GCC), and recognize the need for reliable modeling tools capable of estimating project-specific GHG emissions. As a result, a model framework is proposed as the first step towards a comprehensive modeling tool capable of estimating GHG emissions produced during the entire life-cycle of a road project. The authors disclose that such tool is currently under development

The Full Expression of Talanoa alofa: A Pedagogy to Enrich the Spiritual Wellbeing of Pasifika Children in Early Childhood Education from a Samoan Perspective

This research explores the pedagogical ideas of the concept of “talanoa alofa” from a Samoan perspective, and how it can help enrich the spiritual well-being of Pasifika children, in Pasifika early childhood education (ECE) Aotearoa New Zealand. The study exhibits the views of six Samoan early childhood education (ECE) teachers (a mix of New Zealand born & Samoan born), about the concept of talanoa alofa and spiritual wellbeing from their personal and professional lived experiences. In addition, the study aims to contextualise the knowledge and meaning/s that was discovered/rediscovered from the talatalanoaga into Pasifika ECE. The study utilises the conceptual framework of talanoa as a qualitative research design. Participants were invited to partake in individual talanoaga sessions with the researcher. This gave them a place to freely express themselves and share their thoughts, wisdoms, knowledges and understanding about the topic of interest. Most importantly, it gave them an opportunity to tap into their own spirits to rethink, reflect, reconnect and appreciate their upbringing and lived experiences as positive contribution, to who they have become as Pasifika people in their home countries and Aotearoa New Zealand, especially as parents and educators. Weaving together the meanings, wisdoms and knowledges that were discovered and produced through the talanoaga between the researcher, participants and the literature, this brought about a deeper understanding about the phenomenon. Talanoa alofa is defined in this research as a concept that is derived from the combination, of the term/practise talanoa and the value/principle of alofa. The influence of fa’akerisiano (Christianity) and fa’asamoa (Samoan culture) is also evident in these discussions. In addition, talanoa alofa is identified in the research as one of the most important ways of parenting in the Samoan cultural view. Hence, our proverbs “O tama a manu e fafaga i fuga o laau, a’o tama a tagata e fafaga i upu ma tala” (The offspring of the birds are fed with flowers but the offspring of people are fed with words and stories), O au o matua fanau (The pinnacle of a parents eye are their children). “E leai se gaumata’u na’o le gaualofa” (What you do out of love or with love nurtures and endures - fear does the opposite)” (Tui Atua, 2009, p.54). Furthermore, the relationship between talanoa alofa as a pedagogy, holistic learning and spiritual well-being is identified, examined and discussed in this research. In addition, factors that would possibly influence the implementing of talanoa alofa as a pedagogy are also highlighted and examined

Growth and survival rate vannamei shrimp (Litopenaeus vannamei) in various doses of fertilizer and density

Vannamei shrimp (Litopenaeus vannamei) is a commodity that is expected to not only increase options for farmers but also sustain the rise of shrimp farming business in Indonesia. One important factor in shrimp farming is the availability of feed. In addition to the availability of natural feed during cultivation, stocking density is also very influential in the survival rate and growth of shrimp vannamei. The research was conducted in September-December 2016 farms Bonea Village District of Lasalepa Muna with Test the different dosages with different stocking density. The study used a Random Group Factorial, which is based fertilization (Factor A) with three levels and stocking density (Factor B) as many as three levels, each with three replications so that all 27 units experimental unit. The results showed that the combination of factors dose of 0.7 g of urea + 0.9 g TSP and stocking density factor of 10 individuals per container provides prawn post larvae growth vannamei most excellent and a combination of factors Urea fertilizer dosage of 0.9 g TSP + 1.1 g and stocking density factor of 20 individuals per container provides a survival rate of post larvae vannamei most good. Water quality media for research in the range that is optimal for the growth and survival of post larvae vannamei

Assessing the carbon footprint of road projects and related sustainability initiatives in Abu Dhabi - technical report I: literature review

Energy consumption and the CO2 emission rates in the world are increasing dramatically. Climate change has emerged as an important threat to economic development, environment, and public health. Greenhouse gases are the gases that trap heat in our atmosphere, creating what we call the 'greenhouse effect', that leads to warming the planet Earth. Human activities are contributing several types of greenhouse gases to the atmosphere. The six GHGs identified by the Kyoto Protocol are Carbon Dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFC), Perfluorinated compounds (PFC), and Sulfur hexafluoride (SF6). Each one of these gases can stay in the atmosphere for different amounts of time that can range from a few years to thousands of years. According to the International Panel for Climate Change (IPCC), the total GHG emissions back in 2010 was 49.5 GtCO2eq. The transportation sector is one of the major contributors to global climate change through emissions of CO2 and other GHGs. About 23% of energy-related CO2 emission is contributed by the transportation sector. About 72% of the total direct and indirect GHGs emissions of the transportation sector is caused by roads, making it the top contributing sub-sector in the transportation sector. In the Abu Dhabi Emirate, the total GHG emissions in 2010 were 99,101 Gg CO2 eq. The transportation sector accounted for about 19% of the total emissions and about 63% of the transportation emissions were originated from roads. One of the major strategies to decrease air pollution is to reduce carbon footprint, which can be defined as the total amount of CO2 and other GHGs emitted over the full life cycle of a product or project. As such, for road projects, carbon footprint should be calculated for its life cycle. Sources of carbon emission in road include construction materials, fuel consumption, removal of vegetation and uses of machinery and vehicles. Even though roads often bring major economic and social benefits, they can have a considerable negative impacts on both the community and the surrounding natural environment. These methodologies of CO2 emissions estimation can be divided into three groups. The first and most important group consists of standards and standard-like guidelines that are widely accepted and used. The second group comprises guidelines that focus especially on transport or logistics, but they are often to some extent limited, for example limited to national, regional or mode-specific context. The third group covers industry-led schemes and programs that provide guidelines for a specific branch of industry as how to calculate the carbon footprint. After a careful study of each one of these groups and how some other countries utilized them in their carbon footprint calculation, a selection of one of those groups was made and a modification process took place to allow us to use the method in the Abu Dhabi Emirate. It also helped in determining the best available carbon footprint calculating tool. International cooperation and local action are necessary to mitigate the CO2 emissions. The Government of the United Arab Emirates joined the forces with the international movement towards a clean, sustainable, and environmentally friendly world. The UAE is now fully committed to the United Nations Framework Convention on Climate Change, and creating new laws and regulations to be able to do so. This project is part of the UAE efforts towards making its roads more environmentally sustainable

Assessing the carbon footprint of road projects and related sustainability initiatives in Abu Dhabi - technical report II: carbon footprint from road life cycle and development of a framework for carbon footprint calculation of road in the city of Abu Dhabi

In January 2015, the Infrastructure and Municipal Asset Sector of the Abu Dhabi City Municipality (ADM) invited the Roadway, Transportation and Traffic Safety Research Centre (RTTSRC) at the United Arab Emirates University (UAEU) to submit a proposal for consultancy services regarding carbon footprint calculation and sustainability issues in road projects in the Emirate of Abu Dhabi. The RTTSRC, UAEU responded to ADM invitation and signed a contractual agreement on November 24, 2015 with the ADM (contract number 283/2015) to execute a two year long consultancy project entitled “Assessing the Carbon Footprint of Road Projects and Related Sustainability Initiatives in Abu Dhabi”. The goal of the project is to make road projects in the city of Abu Dhabi more sustainable towards the environment. The project aims to estimate the carbon footprint of road construction and improvement projects in the city with a comprehensive approach considering the life cycle of roads. The objectives of the project are to: • Conduct an extensive literature review of road construction; carbon footprint; sustainability issues; national and international environmental treaties and rules; strategic, environmental and social impact assessment of road projects; • Calculate carbon footprint of road construction, operation and maintenance phases, including development of a framework for carbon footprint calculation of road projects in the city of Abu Dhabi; and • Delineate sustainability issues in road projects and scenario modelling to evaluate potential mitigation measures of reducing the carbon footprint. This report is the revised second technical report that covers the second objective of the project. It delineates development of conceptual frameworks for road carbon footprint estimation, development of a model to estimate greenhouse gas (GHG) emissions over road life cycles, and the application of the model to estimate GHG emissions from three road construction/improvement projects in the Emirate of Abu Dhabi. The second technical report was submitted in May 2017 and the ADM experts provided their review comments on the report in August 2017. This revised report is amended according to the comments, and a separate document addressing the comments is included in Appendix B at the end of this report. Prior to this report, the first technical report covered a comprehensive literature review that was conducted in this study. Since the project aimed at building a model to estimate emissions, a proper guideline from the International Panel for Climate Change (IPCC) was studied in this regard. The software CHANGER was among the different tools that could be used to estimate carbon footprint from road construction. However, CHANGER cannot be used to estimate carbon footprint emissions for the entire life cycle of a road project. After completion of the study, the third and final report will cover scenario modelling for evaluation of potential mitigation measures to reduce carbon emissions from road projects. In this report, a model named “RoadCO2” was developed using Microsoft Excel. It consists of four phases of the road life cycle, namely pre-construction, construction, operation, and maintenance-rehabilitation phases. The model for the construction phase has been designed user-friendly by matching it with ADM standard bill of quantities (BOQ). The operation phase consists of two worksheets: the summary and the input data worksheets. Emissions in the pre-construction and maintenance phase are calculated using worksheets used for the construction phase. A user manual of the Microsoft Excel-based RoadCO2 model is included in Appendix A. The model is included in a CD, attached to this report. The GHG emissions from three road construction/improvement projects in the Abu Dhabi were estimated using the developed RoadCO2 model. The three projects are (1) internal roads and services in Al Rahba City (2) upgrading Al Salam Street (official name is Sheikh Zayed Bin Sultan Street), and (3) widening of the Eastern Abu Dhabi Corniche road. The results were compared to a UAE case study by Huang et al. (2013), which used commercially available software CHANGER. The total emissions from the construction of three case studies were 541, 11568, and 2090 tons CO2 eq/lane/km, respectively. Al Rahba City internal roads and services project is the construction of a 30-km road project consisting of 2 lanes. Among the construction materials used, concrete class k140 contributed the most to GHG emissions (24% of total emissions), followed by aggregate (17%), concrete class k550 (15%) and glass reinforced plastic (15%). Among the equipment used in Al Rahba case study, the highest emission was estimated to be from compactors (4627 tons CO2 eq), followed by loaders (4606 tons CO2 eq), excavators (2770 tons CO2 eq) and tippers (2400 tons CO2 eq). Upgrading Al Salam Street to a project includes the construction of a tunnel of length 3.6 km. The highest emission, in terms of materials, was that of the concrete class k550 (71% of total emissions), followed by steel (13%) and concrete class k140 (5%). In the case of equipment used in Al Salam Street project, the highest emission of 21312 tons CO2 eq. resulted from the trucks used to transport concrete and other materials, followed by soil compactors (3413 tons CO2 eq) and excavators (3204 tons CO2 eq). For the Eastern Abu Dhabi Corniche road widening project, the highest emission was estimated to be from the asphalt materials (41% of total emissions), followed by concrete k140 works (34%), and high density polyethylene (6%). Emissions associated with equipment in this project were the highest from the front shovel (423 tons CO2 eq), followed by the excavators (289 tons CO2 eq). In the operation phase, the traffic operating in the 2.18-km section of Al Salam Street project produces over 37.7 million kg CO2 eq/year. This street has a high traffic volume and a multilane road carrying a large number of heavy vehicles such as trucks and buses. On the other hand, the traffic operating in Al Rahba City road network produces about 2 million kg CO2 eq/year. This city road network is mostly accessed by residents’ passenger cars, which translates into much lighter traffic volumes. Emissions from passenger cars dominate in Al Rahba City internal roads, whereas light and heavy vehicles dominate in the case of Al Salam Street. The IPCC 2006 emission factors are incorporated in the RoadCO2 model. In fact, the UAE is a member of the IPCC. Hence, the Abu Dhabi Road Standards were used in the model development. The input data in the model include materials used in construction, transport mode of materials whether delivered or imported to the site along with the distance travelled, type of equipment operated on the site and type of vehicles and project travelled distances. The data were extracted from their bill of quantities (BOQ). It is highly recommended to collect and use actual data to estimate more accurate results. UAE specific emission factors (i.e., values of the rate of emissions) are not available yet, therefore the IPCC Tier 1 was followed and the default IPCC emission factors were considered in this study. However, it is suggested by (EAD, 2012, 2016) to use local emission factors for more accurate emissions estimation. The model is designed in such a way that it can be updated with local emission factors once available

Assessing the carbon footprint of road projects and related sustainability initiatives in Abu Dhabi - technical Report III (Part I - main report)

Climate change has become a global issue affecting the environment and human health. Due to population growth and their increased energy consumption, generation of greenhouse gases (GHG) has increased significantly. The transportation sector was proven to be the fastest growing major contributor to global climate change accounting for 20% of the total GHG emissions in the United Arab Emirates. The goal of this project is to make road projects in the city of Abu Dhabi more sustainable towards the environment. The project aims to estimate the carbon footprint associated with road projects in the city of Abu Dhabi following a comprehensive approach that considers all activities within the life cycle of roads. The objectives of the project are to: (1) conduct an extensive literature review of road construction; carbon footprint emissions from road projects; and review local sustainability initiatives that are related to road transport, (2) calculate the carbon footprint of road construction and operation phases for three road cases in Abu Dhabi city, including development of a framework for carbon footprint calculation of road projects, and (3) delineate sustainability issues in road projects and conduct scenario modeling to evaluate potential mitigation measures of reducing the carbon footprint associated with these projects. This report is referred to as Technical Report III. It reports on all the tasks of the project, with emphasis on model development and scenario analysis. Although the other two objectives have been covered in previous submissions, the report is considered stand-alone as it provides an updated review of the literature, a description of the developed carbon footprint assessment model, and an updated analysis of the three considered case studies. The report then explains the scenario modeling exercise that was carried on and suggests potential mitigation measures to reduce carbon footprint produced by road projects. Review of the literature regarding carbon footprint of road projects revealed that road transportation is a major contributor to GHG emissions, and its contribution continues to steadily grow despite the latest development in greener practices, technologies, and policies. To remedy this, a number of mitigation measures have been implemented, which have consistently shown to reduce emission levels. However, countries located in the GCC region have shown particularly high road transport GHG emission output; especially, as GHG emission output is normalized by the road length. The literature also revealed that road projects produce GHG emissions at different stages, but road operation is the single, largest GHG producer throughout a road project’s life-cycle. Nonetheless, road construction and rehabilitation may still offer ways to minimize loss of resources, reduce waste generation, and enable the recycling of materials. A number of assessment tools capable of estimating carbon footprint from road-related projects have been developed over the past several years. However, some of these tools are meant to be used on a macro-level by helping decision makers assess the carbon footprint of transport policies. Others are focused on assessing emissions produced by either private vehicles, public transit, or freight transportation. Further, other assessment tools may only estimate emissions based on a single project stage (e.g., construction phase). Another limitation of the developed assessment tools is that they are limited in their geographical usefulness and cannot be applied to achieve the objectives of this project. As such a comprehensive model (referred to as RoadCO2) was developed to estimate the carbon footprint of road projects along the road life cycle (i.e.,pre-construction, construction, operation, maintenance, and rehabilitation phases). RoadCO2 is a web-based model with a database that covers almost all activities that emit GHGs during the road life cycle including those originating from direct or indirect sources. The model follows the conventional Bill of Quantity (BOQ) format for entry of data related to the preconstruction, construction, maintenance and rehabilitation phases. The model can be utilized for planning, screening, sustainability evaluation, and for research purposes. While the model currently uses the IPCC emission factors, it is structured in a way to be able to accommodate local emission factors once available. The RoadCO2 model was used to estimate GHGs emissions from three road projects located in the Abu Dhabi Emirate. These case studies are: (1) Al Rahba City Internal Roads and services, (2) upgrading of Al Salam Street to an expressway, and (3) widening of the Eastern Corniche Road. Results obtained through the model demonstrate that the operation phase is the main contributor to GHG emissions, with a share of more than 80% of the total due to emissions from vehicles and road lighting. Emissions from the construction of the investigated road cases were found to be 43, 350, and 16 thousand ton CO2 eq, respectively. Of these, road works contributed the most to GHG emissions, followed by stormwater works. Other categories considered in the construction phase contributed almost equal proportion to total GHG emissions, but vary from one project to another. The relative contribution of material and equipment (including their transport to the sites) to GHG emissions of the studied cases varies. For the case of Al Rahab City, about 30% of the emissions was due to material use while 70% was due to equipment use. For the case of Al Salam Street and the Corniche Road, a higher relative contribution of material to GHG emissions was found (about 80%) as compared to emissions due to the use of equipment. This is mainly due to the high usage of concrete and steel in constructing the tunnel for Al Salam Street case and due to the high contribution of road works as well as the use of concrete for relocating the existed sub-surface network of utilities in the case of the Corniche Road. In the operation phase, the traffic operating in the 2.18-km section of Al Salam Street project produces over 31,068 ton CO2 eq/year, whereas traffic operating on the road network within Al Rahba City produces about 2,891 ton CO2 eq/year. This significant difference is in line with the major dissimilarities between the two transportation facilities. Emissions from passenger cars dominate in Al Rahba city internal roads, whereas light and heavy vehicles dominate in the case of Al Salam Street. Street lighting was also found to be a major contributor to GHG emissions of Al Salam Street and the Corniche Road case studies. However, both irrigation and sequestration were found to have very low impact on the overall GHG emissions rates. The estimated annual carbon emissions from Al Salam Street is 46,000 ton CO2 eq while emissions from Al Rahba Roads contribute about 10,000 ton CO2 eq. If one is to consider the effect of road works and the activities of the operation phase excluding those associated with vehicle movement, the emission rates associated with the three case studies conducted in this project expressed in kg CO2 eq/m/yr would be 30 for the case of Al Rahba City, 89.2 for the case of Al Salam Street, and 62.1 for the case of the Eastern Abu Dhabi Corniche Road. These values are in the upper range of those reported for some European countries, due possibly to several factors among which are higher irrigation rates of road-planted trees in the UAE, a lower role of sequestration, and higher emissions from use of concrete made of Portland cement. Thirteen different scenarios were explored to assess their impact on reducing GHG emissions during the construction and operation phase of road projects. The baseline for the investigated scenario are the three investigated case studies. The explored scenarios either altered the activity data or the emission factor associated with the activity. Results showed that the use of LED lights would have a significant impact on reducing GHG emissions of road projects, followed by the use of 25% solar energy for lighting, followed by almost equal impact of using ground granulated blast furnace slag in concrete mix, complete utilization of TSE for irrigation, and increasing the use of LNG by 25% for LDV. When some of the explored individual scenarios were combined, a significant potential impact could be achieved, with an overall GHG emission reduction of 15 to 40% during the road lifecycle. It was found through scenario analysis that recycling asphalt, recycling aggregate, and reducing water usage for road irrigation do not cause a great potential to reduce GHG emissions for road infrastructure. However, these alternatives may offer other environmental benefits and could save valuable resources. This report suggests several recommendations for possibly other studies that could build up on the achievements made under this project and could result in better estimation of the emitted GHG during the road life cycle

RoadCO2: a web-based tool for estimation of greenhouse gas emissions of road projects

A number of countries have recognized the need to quantify the greenhouse gas (GHG) emissions produced by road transportation. As a result, several estimation tools have been developed during the last decade. However, the available tools do not capture all activities contributing to GHG emissions during the life cycle of road projects. This paper describes the development of a comprehensive web-based tool that can be used to quantify direct and embodied emissions from all activities associated with different phases of road projects. The tool, called RoadCO2, accounts for all possible activities that may be encountered during the pre-construction, construction, operation, maintenance, and rehabilitation phases of a road project. Although RoadCO2 currently uses emission factors established by the Intergovernmental Panel on Climate Change (IPCC), the tool has the flexibility to accommodate country-specific emission factors, if available