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Off-Road Cycling Facilities - Sight Triangle Requirements at Stop Controlled Driveway and Side Road Crossings

mar, 11/10/2020 - 18:07
Off-Road Cycling Facilities - Sight Triangle Requirements at Stop Controlled Driveway and Side Road Crossings
by Mollett,C; Gates-Crease,W-C; Repovski,J.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5134 - INTERNET


Increasingly local and regional municipalities are constructing bicycle facilities within the boulevard, whether they be dedicated bicycle lanes or multi-use pathways (MUP’s). In addition, cyclists also often use sidewalks. Cyclists can travel up to 20 km/h and where these cycling facilities cross non-signalized driveways and local roads there is a significant potential for conflict between cyclists and exiting drivers, especially considering that many drivers are “non-compliant” and do not always stop in advance of the cycling facility. Therefore such “non-compliant” drivers and cyclists should have enough sight distance to allow them time to observe, initiate and execute the desired actions to avoid a collision. This paper will show that there cannot be a “one size fit all” solution because sight distance requirements are a function of several variables that can differ from location to location. The most critical variable being how far the facility is located from the curb. It is therefore imperative that required sight triangle dimensions be calculated on a site by site basis. The paper will develop and present the mathematical models and tools that can be used to calculate the sight triangle dimensions for any location – for both “compliant” and “non-compliant” drivers. From an infrastructure design perspective it will increase our understanding on how modifying certain cycling facility design parameters will impact sight triangle dimensions – and hence how we can reduce the risk of conflict between drivers and cyclists. From a land development perspective the models and tools will assist planners and engineers to determine the size of daylight triangle areas that should be kept free and clear of any potential sight line obstructions. when and what type of mitigating measures may be required to reduce conflicts. The TAC Guidelines provides no guidance on sight distance requirements between driveway vehicles and cyclists on cycling facilities. The research aims to fill this gap by using a first principle based approach towards developing guidelines and tools we can use to minimize conflicts between vehicles and cyclists.

Nanaimo Goes Dutch: Adopting Raised Local Intersections

mar, 11/10/2020 - 16:53
Nanaimo Goes Dutch: Adopting Raised Local Intersections
by Fipke,A; Symons,R.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5133 - INTERNET


Nanaimo has been developing its Complete Street Design Guideline while in parallel putting it into practice on the Metral Drive corridor, showcasing sustainable urban transportation design in the City. The guidelines set a high bar for all future street design, reallocating the right-of-way in an equitable manner and managing conflicts safely. The immediate implementation of the guidelines on Metral Drive will demonstrate how such designs can contribute to community wellbeing by providing a safe environment that enables people to choose active and healthier travel options while also enhancing the streetscape. Metral Drive currently has varying levels of pedestrian provision from sidewalks to gravel shoulders and no cycling provisions. The inconsistencies are not conducive to attracting people out of their cars. Using the guidelines to develop the Metral Drive detailed design, the City will provide people, regardless of their age, income or physical ability, with safe travel options to the Woodgrove Centre, one of Nanaimo’s key mobility and economic hubs. While the guideline recommends best practice levels of space and separation, it also includes retrofit guidance and speaks to how similar outcomes can be achieved for lower costs or in constrained rights of way. The guideline and Metral Drive design include many best practices, but most innovative is the adoption of Dutch design principles prioritizing active modes through design with continuous sidewalks and bike paths across local roads. While this old design technique is often used in Europe, we believe it has not been fully implemented in Canada. To understand the value this would add to the Canadian context and confirm our belief that this technique has not been widely adopted, the team queried many well-respected planners, engineers, and advocates through twitter to try and find examples of such designs. It revealed nobody in Canada appears to be adopting such designs and Nanaimo aims to change that! Metral Drive will provide a Canadian showcase for Dutch-style intersections in Canada prioritizing the safety of our most vulnerable and will position Nanaimo as an example of best practice for all communities in Canada to reference.

Multi-Criteria Risk-Informed Capital Renewal Planning: A Pavement Management Application

mar, 11/10/2020 - 16:24
Multi-Criteria Risk-Informed Capital Renewal Planning: A Pavement Management Application
by Rashedi,R; Maher,M; Yuan,A.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5132 - INTERNET


Developing a risk-informed decision making framework is crucial to address two major aspects of managing road networks. The first is the development of deterioration models to capture physical deterioration trends based on various road attribute combinations. The second is the development of an optimization process for capital planning that integrates lifecycle cost analysis, risk analysis, effectiveness of maintenance and rehabilitation technologies, network effects, cross-sectoral interactions, and strategies for asset inspection with dynamic model updating. This session discusses techniques for performance modeling and risk-informed decision making methods with a focus on municipal pavement assets. Canadian municipal case studies are presented to show the effectiveness of the methods presented and to discuss real-life implications.

Moisture Damage in Asphalt Concrete Mixtures: State of the Art and Critical Review of the Test Methods

mar, 11/10/2020 - 16:07
Moisture Damage in Asphalt Concrete Mixtures: State of the Art and Critical Review of the Test Methods
by Tavassoti,P; Baaj,H.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5131 - INTERNET


Moisture-induced damage is among the four prevalent causes of premature failure of flexible pavements in Canada. Research on moisture damage evaluation of asphalt concrete mixtures dates back to approximately one century ago. However, relating the field performance of mixes to their associated properties captured through laboratory test methods is not fully developed yet. Several test methods have been utilized over the last few decades to assess the moisture-induced damage of mixes in the laboratory scale. Studying the Tensile Strength Ratio (TSR) or loss of indirect tensile strength (ITS) due to moisture conditioning of specimens with or without (a) freeze-thaw cycle(s) has been the most commonly used method in North America. Review of case studies indicates major shortcomings of this technique. For instance, in many cases a mix may pass the minimum TSR requirements in the laboratory, but would fail in the field and vice-versa. Therefore, many transportation agencies have been recently investing in finding alternative test methods such as Hamburg Wheel-Tracking Test (HWTT) and Moisture-induced stress tester (MiST) to better predict the moisture-related performance of flexible pavements. This study, provides a critical review of the existing methods for evaluation of moisture damage in asphalt mixtures along with their strengths and weaknesses for this purpose. The major parameters that contribute to this complex phenomenon are also discussed. A synthesis of the state of practice for design specifications and materials acceptance with respect to moisture damage by different agencies is also provided. Finally, the need to use domestically calibrated moisture conditioning, evaluation practices, and establishing customized acceptance thresholds that suit the climatic conditions in Canadian environment is highlighted. Recommendations are provided for an improved moisture damage assessment framework, based on the lessons learned from the past experiences as well as the identified promising techniques.

Mechanical and Durability Performance of an Innovative In-Situ Concrete Pavement Repair Patch

lun, 11/09/2020 - 21:17
Mechanical and Durability Performance of an Innovative In-Situ Concrete Pavement Repair Patch
by Booya,E; Loh,P; Gardonio,D; Adesina,A; Das,S.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5130 - INTERNET


Concrete roads crack and deteriorate due to severe service loadings, de-icing materials, freeze-thaw cycles, etc. The replacement cost of existing deficient concrete roads is expensive. Moreover, the design of maintenance materials requires the use of energy-efficient materials with a low environmental impact. Facca Incorporated, in collaboration with Dura Concrete Canada Inc., located in Ontario has been developing an innovative cementitious composite for different construction applications. One of these applications is the use of Ultra-High-Performance Concrete (UHPC) and Engineered Cementitious Composites (ECC) as a partial patch repair for concrete roads. The mechanical and durability performance of UHPC and ECC mixtures were investigated. The mechanical performance of the mixtures was assessed by means of compressive, and flexural strength. While, the durability of the mixtures was investigated and evaluated by the means of rapid chloride penetration, absorption, and plastic shrinkage. To compare the mixture's performance in the field, a location in the City of Windsor was selected. These innovative in-situ repair materials were applied in thickness varying from 40 to 60 mm. The selected road was closed, milled, prepared, repair materials applied and completed within 24 hours. The strength gain in 24 hours of both UHPC and ECC were acceptable to open the roads to traffic after 48 hours. Laboratory and in-field results and observations for the road repair materials, showed superior mechanical and durability characteristics.

Market Parkade, City of Guelph

lun, 11/09/2020 - 20:39
Market Parkade, City of Guelph
by Zettle,J.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5129 - INTERNET


The City of Guelph has opened an industry leading new parking garage powered entirely by renewable energy sources, making it Guelph’s first energy self-sufficient and self-sustaining parking facility. Supporting the City of Guelph’s commitment to its corporate 100RE target through which all City facilities and operations will use 100 per cent renewable energy by 2050, the new garage has 496 stalls, EV charging, accessible stalls and secure bicycle parking. The facility is a Net Zero Energy site with over five hundred solar panels installed on the roof, generating nearly 200,000 kWh/year. As the first parking garage built in the City of Guelph in over thirty years, the new Market Parkade is positioned to address the emerging issues posed by climate change by depending entirely on renewable energy sources to power its EV charging stations, lights, security and parking access and revenue control equipment. The facility starts with four EV charging stations and has the infrastructure to expand to eighty EV charging stations as consumers’ usage patterns change. Moreover, the facility was built using the CANADACAR Parking Structure System: a pre-engineered, prefabricated building system that utilizes the most advanced, innovative technique of construction resulting in free span modular parking bays. The CANADACAR Parking Structure System offers the following benefits: cost efficient, reduced maintenance costs, driver/pedestrian safe, reduced construction time, increased longevity, greater flexibility and increased volume, all components in reducing the initial and ongoing carbon footprint of the facility and its operation. The facility was built with a view to the lifecycle cost to maintain the structure. Importantly, the facility was built as the first step in realizing the City of Guelph’s goal of using only 100% renewable energy sources by 2050. The new garage will produce significant cost savings in its ongoing operation and maintenance. From an energy perspective, the facility has a 188kW electrical generation capacity expected to produce 200,000 kWh/year from renewable energy sources. The electricity produced will meet the needs of the facility as well as the annual electricity required to power the four EV charging stations. The City will return any excess electricity to the grid for use in other facilities. This self-sufficiency will save ~$35,000 annually in operating expenses alone.

Link Slabs in Highway 17 over Battle River Bridge

lun, 11/09/2020 - 20:21
Link Slabs in Highway 17 over Battle River Bridge
by DeGrow,K.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5128 - INTERNET


Project achievements were: Eliminating all four expansion joints using innovative link slab and semi-integral abutment details. To our knowledge the link slabs are the rst that used hooked steel bres in an exposed concrete deck in Saskatchewan/Alberta. The link slabs are performing well after 3 years in-service; The service life of the 56-year old structure was extended by 40+ years and reduced the carbon footprint of the bridge by salvaging most bridge elements. Leaking water through bridge deck expansion joints is one of the leading causes for bridge deterioration and results in high priority, costly, and challenging repairs to the bridge elements below them. Using life cycle cost analysis, semi-integral abutments and link slabs at the piers were the most practical and cost-effective solutions. Although many jurisdictions utilize semi-integral abutments to eliminate abutment joints, the use of link slabs to eliminate pier joints does not share the same popularity. Although the link slab concept is not new, a lack of historical performance data has made some bridge owners reluctant to use this concept. Through our extensive research and careful design, we encouraged the client to proceed with link slabs. In additional to the semi-integral abutment conversion and link slab installation, the following repairs were also completed: Partial depth deck rehabilitation and deck widening; Girder strengthening to support new standard design vehicles Upgraded bridge and approach railings to current standards; and Lifted superstructure to facilitate substructure repairs and a bearing replacement. Some of the unique, challenging, innovative, environmental, and sustainable achievements on this project were: Eliminating all expansion joints using innovative link slab details. To our knowledge, these are the first link slabs that have used hooked fibre reinforced concrete in the exposed concrete deck. These details will significantly improve the exposure condition of the underlying elements from chlorides and moisture. This will extend the service life of the bridge and reduce future costs. After being in-service for three-years, the link slabs are performing well with no visible signs of leakage. Extending the service life of a 56-year old structure by 40+ years; Reducing the carbon footprint of the bridge by salvaging most of a 56-year old structure rather than disposing of it and fabricating new bridge elements. The existing elements were repaired, modified, or strengthened to improve their condition, functionality, and service life.

Invisible Trace Evidence: Using Environmental DNA (eDNA) to Detect Species in Aquatic Ecosystems

lun, 11/09/2020 - 19:55
Invisible Trace Evidence: Using Environmental DNA (eDNA) to Detect Species in Aquatic Ecosystems
by Routledge,K.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5127 - INTERNET


Environmental DNA is an innovative method to collect accurate data is needed to predict presence of species at risk and other species that use aquatic habitats for impact assessment, meet regulatory requirements and identify specific mitigation to address potential adverse effects. This method is particularly suited to linear transportation projects which typically cross or impact multiple waterbodies. In British Columbia, federal and provincial guidance require stringent sampling methods to demonstrate presence / absence of species at risk. Trapping and other direct sampling methods can have significant impacts on the target species (e.g., mortality). As organisms shed deoxyribonucleic acid (DNA) in aquatic environments, eDNA samples can be collected from these environments. Studies of eDNA have gained scientific and regulatory acceptance in recent years, especially for surveying at-risk aquatic and semi-aquatic species. Benefits of this type of sampling include: Lower costs - eDNA field sampling requires only the collection of water samples, avoiding complex multi-day conventional sampling programs (e.g., baited trapping, electro-shocking and/or physical searches. Once baseline primer development is complete, costs can be 10% or less of conventional methods. Non-invasive – avoids mortality risk due to physical injury or pathogen transfer associated with conventional methods Highly accurate – eDNA sampling when correctly implemented, is definitive for detection of presence and very sensitive to detection of aquatic species; The credibility of eDNA survey data, however, depends on adequate methodological validation and verification; accurate results require rigour during field sampling, sample processing, laboratory analysis, and primer design and/or verification. Hemmera recently developed accepted standards for collection of eDNA for the BC Ministry of Environment and has completed for multiple transportation projects including MOTI’s South Fraser Perimeter Road (target species - red-legged frog and Pacific water shrew), MOTI’s Kicking Horse Canyon Phase 4 (target species Western toad) and TransLink’s Surrey Langley SkyTrain project (target species – multiple salmonids, Pacific water shrew and red-legged frog).

Investigating the Freeze-Thaw Damage in Asphalt Concrete Using Imaging Techniques

lun, 11/09/2020 - 19:19
Investigating the Freeze-Thaw Damage in Asphalt Concrete Using Imaging Techniques
by Alawneh,M; Soliman,H; Anthony,A.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5126 - INTERNET


In cold regions, asphalt concrete (AC) pavements experience freeze-thaw (F-T) cycles. F-T cycles can cause damage and disintegration of AC mixtures, which cause significant operational problems and a reduction in the service life of AC pavements. The evolution of the internal structure of an AC mix due to exposure to F-T cycles should be explored to have a better understanding of the mechanism of F-T damage in the mix. In this study, different AC specimens were evaluated before and after F-T cycles using two techniques: indirect tension test (IDT) to evaluate strength deterioration of specimens, and imaging techniques to capture changes in the internal structure of specimens. Three imaging techniques were used in this project: digital camera, stereomicroscope, and X-ray computer tomography (CT) scan system. Each technique has its potentials to show the internal damage details. AC specimens have been assessed at different levels of F-T cycles. 2D and 3D images for the internal structure of the specimens were collected and analyzed at 0, 15, 30 and 45 F-T cycles. The captured images will be analyzed to quantify the F-T damage according to adhesion failure (%), cohesion failure (%), broken aggregate (%), and the total length of microcracks (mm). The results from image analysis will be correlated to IDT results.

Improving the Efficacy of Learning Bridge Inspection & Maintenance

lun, 11/09/2020 - 18:59
Improving the Efficacy of Learning Bridge Inspection & Maintenance
by Warren,J.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5125 - INTERNET


It’s well known that using a variety of instructional methods increases participants’ retention of the content and their enjoyment of the course. Videos are a good way to appeal to visual and auditory learners, with the added appeal that the content is always consistently delivered as intended. After 25 years of using the same Bridge Inspection & Maintenance instructional video in OGRA’s Bridge & Culvert Management Course, the video was dated. To create a top-quality, technically accurate product, OGRA recruited assistance from industry subject matter experts who teach for OGRA and are leaders at their organizations – 407 ETR, GHD, and the Town of Innisfil. Thanks to these experts, the content was reviewed to ensure technical accuracy and consistency with the Ontario Structure Inspection Manual. Of equal importance to our students, the minutiae of the content were reviewed and debated at length to ensure the information is practical and can realistically be employed when they return to their organization. More importantly, the shots were all updated to demonstrate the best safety practices to reinforce the important role safety plays in all our activities. In planning the video, we included relevant technology that should be used, such as mobile devices. Thanks to our subject matter experts and their generous employers, we were able to include current practices and equipment such as a Bridgemaster truck. To appeal to visual learners, we used a high-resolution camera. To get unique shots at interesting angles, a drone was employed. The animations have been updated to make them realistic and better show key concepts. For auditory learners, we used technology which provided crisp sound without distracting background noise. In reviewing the old video, it was quickly noted the people shown in the video do not represent today’s diverse workforce. To rectify this, both a female and male host were used to present information and for voice-overs. When filming bridge inspection or maintenance, we ensured a variety of people were used, who are all currently involved in the infrastructure industry.

Impact of Road Geometry and Thickness on Pavement Behaviour using PSIPave 3D™

lun, 11/09/2020 - 18:40
Impact of Road Geometry and Thickness on Pavement Behaviour using PSIPave 3D™
by Forghani,F; Tighe,S; Henderson,V; Becke,M; Soares,R; Haichert,R.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5124 - INTERNET


Roads allow for the transportation of people and goods, thus fostering economic growth and acting as an integral piece of infrastructure in any community. The design of the pavement structure and geometry of a road has a contribution to the long-term performance of the road. The primary objective is to distribute the stresses from traffic on the surface to the layers below and ultimately the in-situ subgrade. By properly selecting designs and planning strategies, the deterioration rate can be decreased, saving costs for maintenance and repairs and minimizing disruption to users while providing a better performing asset. Many current pavement design methods use empirical predictions and do not truly account for material behaviour under loads. Conventional pavement design methods such as American Association of State Highway and Transportation Officials 93 (AASHTO 93) and Shell Design Charts for Flexible Pavements (Shell) express traffic in the form of equivalent single axle loads which may not accurately reflect the various truck loading configurations to which a pavement is subjected. This research is done in collaboration with PSI Technologies Inc. (PSI) and the City of Hamilton to compare conventional pavement design methods and the effect of road geometry on pavement structure behaviour. PSI has developed a three-dimensional finite element pavement design method, PSIPave 3D™. This method is a mechanistic model that fully describes the pavement structure behaviour considering traffic loading, roadway geometry and material properties. AASHTO 93, Shell, and Mechanistic-Empirical Pavement Design Guide (MEPDG) do not fully consider the impact of road geometry and material behaviour. This project considers a flexible, urban collector road section in Hamilton, ON. Twelve cases of pavement structure reconstruction and roadway geometry have been developed. Using PSIPave 3D™, the designs and performance predictions for each case are discussed in this work.

Governance Participation Strategies for Mobility as a Service

ven, 11/06/2020 - 21:36
Governance Participation Strategies for Mobility as a Service
by Underhill,B.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5123 - INTERNET


New and smart mobility are transforming the transportation landscape globally. As the landscape evolves, it will become increasingly viable for travellers to meet their mobility needs by purchasing rides or seats instead of vehicles or other transportation assets. Mobility as a Service (MaaS) is an emerging framework that unites public and private transportation services through a digital medium (app or platform) to enable multimodal trip planning, integrated payment, and price bundling and incentives. While countless benefits and opportunities come with the promise of MaaS, there are areas where the concept could fall short: a lack of government intervention, for example, could result in proprietary walled gardens where private operators offer their services without complete multimodal offerings across a region. It will be critical to provide a wide range of mobility services within one or more comprehensive MaaS platforms to achieve efficient, customer-friendly MaaS options. Currently, governance in MaaS is relatively limited in Canada, with only a few transportation agencies studying how to participate in the field. In Metro Vancouver the ride-purchasing market is already well established, with many people choosing shared transportation (public transit, car-share, vehicle-for-hire, bikeshare) instead of owning a personal vehicle. To prepare for further transformation in the transportation landscape, TransLink retained WSP to develop a discussion paper to help the agency define its role in MaaS. The paper identifies and assesses approaches TransLink could take to transport system management (i.e., regulatory oversight of private-sector industry participants); with regards to the provision of customerfacing MaaS services; and with respect to perceived risks of under- and over-involvement in MaaS. The goal of this paper was to identify possibilities for TransLink to participate in MaaS, as well as preparing the agency for future mobility disruptions. The paper was developed through a desktop review of current MaaS examples, and interviews and workshops with TransLink executives to align the paper with the agency’s priorities. WSP’s global thought leadership and experience with MaaS was leveraged by engaging our MaaS leaders in Sweden, the United Kingdom, the United States, and Australia to share how MaaS is being deployed elsewhere in the world.

Going Green by Seeing the Greens

ven, 11/06/2020 - 20:43
Going Green by Seeing the Greens
by Kent,G; Choudhry,O.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5122 - INTERNET


The City of Ottawa "EcoDrive II" pilot project investigated the potential environmental and fuel efficiency benefits of giving City fleet drivers advanced signal information across the entire 1,200 traffic signal system. Known as Green Light Optimal Speed Advisory (GLOSA), drivers were equipped with a mobile app that provided real-time information about the current signal status (e.g., red vs. green), time remaining for that status, and an advisory travel speed drivers should maintain, if possible, to reach the signal on a green cycle. The app was also designed to record real-time engine and fuel consumption information using the On-Board Diagnostic (OBD) unit. The drivers drove both with and without GLOSA information provided on the mobile app, to measure whether their driving habits were altered by the provision on the GLOSA information and if there was a measurable savings in fuel consumption from differing driving habits. As these City fleet vehicles travel the network conducting their normal business duties, GLOSA and OBD information were logged on a per-second basis for analysis. A total of 23,980 kilometers were travelled and 29,393 signals traversed by the seven fleet vehicles equipped in the pilot project, and over 4,660 litres of fuel consumed. The City used a cellular-based system for communicating with the vehicle, as opposed to localized DSRC communications, which allowed for a faster and more cost-effective deployment of the technology. The City of Ottawa also provided a unique environment to test the benefits of providing drivers with GLOSA information when use in an actuated signal system. Four key influences on the results were the acceptance of the technology by the driver, variation in weekly tasks, area/urban density, and time of day. Fuel savings were found to range from negligible amounts to 14 percent for the most engaged driver, with an average savings across the fleet of 5 percent during the two-month test period. At a savings rate of 0.3L/hr of travel, a city-sized fleet of 900 vehicles could save over 100,000 litres annually. The project was funded through the Advance Connectivity and Automation in the Transportation System (ACATS) program by Transport Canada.

Geotechnical Evaluation of Alternative Configurations of Integral Abutment Bridge Approach Slabs for Mitigation of Asphalt Distress

ven, 11/06/2020 - 20:10
Geotechnical Evaluation of Alternative Configurations of Integral Abutment Bridge Approach Slabs for Mitigation of Asphalt Distress
by Carvajal,J-C; Wilson,P; Ma,D; Sangiuliano,T; Mermigas,K; Chatterji,PK.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5121 - INTERNET


The Ministry of Transportation of Ontario (MTO) is considering alternative approach slab configurations to reduce the frequency and severity of pavement surface distress that are commonly observed at the end of approach slabs of bridges with integral abutments. The MTO uses a standard approach slab that comprises a 6 m-long RC slab set near road grade and surfaced with 90 mm of asphalt. This slab configuration has performed satisfactorily for up to 10 mm of abutment displacement. However, asphalt cracking and settlements are observed at the far end of the approach slabs for displacements greater than 10 mm. This paper presents the results of a study to find alternative approach slab configurations that can accommodate up to 25 mm of abutment/slab displacement and reduce the maintenance cost of IAB in Ontario. As an alternative to the standard approach slab, the MTO is considering a number of approach slab designs ranging from angled slabs to buried slabs, with or without sleeper slabs, and potentially combined with soil or asphalt reinforcement, to reduce the effect of the underlying ground settlement on the transition from the approach slab to the bridge deck. FEA was used to analyze the failure mechanism and the strain demands on the asphalt pavement. Different configurations of the slab were considered: slab inclination, slab depth below road grade, backfill reinforcement, installation of a buried sleeper, asphalt thickness and asphalt reinforcement. Based on these, the proposed slab configuration includes a 250 mm-thick asphalt reinforced with 3 layers of GlasGrid plus a 200 mm-depth, 1V:20H inclined approach slab supported on a buried sleeper at the far end of the approach slab. The analysis showed that the proposed slab configuration can reduce in 70% the strain demands in the asphalt, in comparison with the current MTO slab configuration, and prevent cracking and settlements at the far end of the approach slab for 25 mm of displacement.

Evaluation of Modified H-Piles Subject to Lateral Loading for Sound Wall Applications

mer, 11/04/2020 - 21:10
Evaluation of Modified H-Piles Subject to Lateral Loading for Sound Wall Applications
by El Naggar,H; Elsharnouby,M; Mroz,D.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5120 - INTERNET


Sound walls are utilized for mitigating ambient noise caused by traffic or industrial and commercial activities. Sound wall foundations are typically subject to large lateral load and bending moment produced by wind. Drilled shafts are conventionally used as foundations for sound walls, which can be constructed to provide significant lateral resistance. Using H-piles as an alternative can provide faster installation and immediate utilization, however, they may lack the required stiffness to adequately support these forces. To address this, a modified H-Pile concept was developed which includes one or two plates welded along the pile web to increase the pile-soil surface area perpendicular to lateral loading thus increasing its resistance. In addition, using steel piles improves the sustainability of the system. Used steel is manufactured using two processes BOF and EAF. The recycled content ranges from 37% to 89%. A full-scale pile load testing program comprising monotonic and cyclic lateral load tests was performed on fourteen steel piles including unmodified steel piles to comparatively evaluate the influence of adding plates to H-piles. Two drilled shafts were also tested as a baseline to compare current practice against the proposed system. A numerical model was developed with LPILE which was calibrated and validated using the experimental results and then used to conduct a parametric study considering different plate dimensions and a range of practical soil conditions. A second numerical model was developed using GSNAP to extend the cyclic lateral load analysis to simulate higher loads and more load cycles. H-piles modified with plates had an approximately 22% higher lateral load capacity. The corresponding parametric study demonstrated that widening the plate is typically more efficient for increasing the pile’s lateral capacity than increasing the plate length. The cyclic lateral load tests revealed that the lateral stiffness of the novel piles remains approximately constant within 100 cycles. The GSNAP model simulated that the pile will experience less than 10 mm of ground level deflection at 1000 cycles of the design lateral load.

Elgin Street Road Safety Improvements

mer, 11/04/2020 - 20:48
Elgin Street Road Safety Improvements
by Clarke,R.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5119 - INTERNET


Elgin Street is a historically busy thoroughfare in central Ottawa that is currently being reconstructed to support a 30km/h operating speed, along with fewer vehicle lanes and an enhanced pedestrian realm. The new design aligns with the City’s Road Safety Action Plan and is expected to reduce the number of collisions while significantly improving the public realm, especially for vulnerable road users. In Ottawa, between 2013 and 2017, almost 50% of fatal and major injuries occurred due to vehicle collisions at signalized intersections. In this commercial business district, 71% of fatal and major injury collisions involved pedestrians, as compared to the citywide average of 26%. With seven signalized intersections and high pedestrian volumes, significant safety benefits are anticipated as a result of this project. Prior to the reconstruction, Elgin Street was auto-focused, consisting of four travel lanes with off-peak parking on both sides. No auxiliary turning lanes resulted in unsafe slip-around movements and weaving through intersections. The proposed design will ensure safer, single-file vehicle operation and improved sightlines for all users. The sidewalks were also very narrow with over 800 pedestrians typically walking along Elgin Street during the afternoon peak hour. The proposed design reduces the number of vehicle lanes from four to two, plus auxiliary lanes, which allows for the reallocation of space to sidewalks. The plan also incorporates “flex space” which can be programmed for pedestrian use, patio space or on-street parking. This results in generous sidewalks and the ability to provide seating, artwork and landscaping, as well as accessible parking and loading opportunities at various times throughout the day and year. Elgin Street will be the first arterial mainstreet in Ottawa with a posted speed limit of 30km/h, which is expected to reduce the risk and severity of collisions while promoting an enhanced public realm. To support a lower speed limit, the design includes four raised intersections, tighter curb radii, curb extensions and narrow vehicle lanes. The design concept for this roadway can be applied to other municipalities by referring to Ottawa’s Complete Streets Guidelines.

Dowel Bar Alignment in Concrete Pavements - 21st Century Standards and Methods

mer, 11/04/2020 - 20:18
Dowel Bar Alignment in Concrete Pavements - 21st Century Standards and Methods
by Kivi,A.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5118 - INTERNET


Dowel bars are used in the construction of jointed concrete pavements to provide load transfer, which is vital to long performance. Misaligned or improperly placed dowels may cause poor joint performance that would lead to pavement distresses, such as cracking, spalling or faulting. Dowel bar misalignment can be categorized into five generalized categories: horizontal translation, vertical translation, side shift, horizontal rotation and vertical rotation. Depending on the type of misalignment, the impact can individual dowel bar effectiveness or globally affect free joint movement. Different agencies have adopted different standards with regards to dowel bar alignment, tolerances for misalignments and methods of quality assurance verification. Several types of non-destructive testing equipment of are used to measure dowel and tie bar alignment in concrete pavement joints. The MIT-SCAN device, a magnetic imaging tomography scanner, and Ground Penetrating Radar (GPR) are the most common devices for measuring the position and alignment of dowel bars for quality assurance or forensic purposes. This paper provides an overview of the usage of dowel bars in jointed concrete pavements, a review of current dowel bar tolerance standards for a sampling of Canadian and US jurisdictions and a detailed description of the state-of-practice for dowel bar alignment evaluation with North American agencies.

Development of Collision Adjustment Factors for the Canadian Traffic Signal Warrant Matrix Procedure

mer, 11/04/2020 - 19:47
Development of Collision Adjustment Factors for the Canadian Traffic Signal Warrant Matrix Procedure
by Northmore,A; Hildebrand,E.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5117 - INTERNET


Traffic signal warrants (TSWs) are important tools for traffic engineers because they provide an objective shorthand means of identifying whether a net benefit would result from signalizing an intersection. This decision can impact numerous operational facets; consequently, most TSW systems consider several factors when estimating an overall impact. The Canadian Traffic Signal Warrant Matrix Procedure, originally published by the Transportation Association of Canada (TAC) in 2003 with subsequent minor adjustments, does not have a collision history component: a common feature in other TSWs. This creates challenges for practitioners investigating the safety impacts of signalization because the lack of a standardized approach can lead to inconsistency in their findings. This research developed collision adjustment factors (CAFs) that convert the collision history for a site into points that supplement the existing TAC warrant procedure score outputs. The CAFs were developed based on recent research that estimates expected changes in collision severity and frequency in North America due to signalization, with the intent that they can be broadly used by all Canadian jurisdictions. Additionally, the procedure used to develop the national CAFs in this research can be employed by jurisdictions analyze their intersections based on local data.

Development of a methodology to estimate ESALs for Widebase Steering Tires

mer, 11/04/2020 - 16:17
Development of a methodology to estimate ESALs for Widebase Steering Tires
by Bradley,A; Thiam,P-M.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5116 - INTERNET


British Columbia Ministry of Transportation and Infrastructure (TRAN), and other Canadian regulators, utilize the ESAL concept for vehicle impact evaluations and(or) pavement design. TAC’s ESAL equations originally were developed in RTAC’s Heavy Vehicle Weights and Dimensions Study (RTAC, 1986) and are widely accepted by the Canadian transportation industry. Unfortunately, TAC’s ESAL equations do not account for tire size and, consequently, overestimate steering axle impacts when those axles are equipped with widebase steering tires. Most new vehicles proposed for use in B.C. (or in other Provinces) feature tridem drive tractors which, by regulation, must carry at least 25% - 27% of the drive group weight on the steering axle—these heavy loads necessitate the use of widebase steering tires. In order to optimize high efficiency truck configurations in Canada, therefore, accurate estimates of widebase steering tire ESALs are needed. This paper describes a methodology that was recently developed by FPInnovations, in consultation with TRAN, to estimate ESALs for widebase steering tires. Using layered elastic pavement modeling, FPInnovations evaluated key strain responses to widebase steering tire traffic in the 14 RTAC-86 test pavement sections. The results were transformed to estimates of pavement life and then calibrated to RTAC-86’s single-axle/single-tire ESAL model to develop ESAL relations for 8 popular North American steering tire sizes, including four widebase steering tires. The ESAL relations produced in this research extend the TAC ESAL equations to all popular North American widebase steering tire sizes and offer regulators, academics, and consultants a means to more accurately estimate steering tire pavement impacts. The paper includes a practical example of the use of these widebase steering tire ESAL equations. In order that new truck configurations in B.C. evolve to create less road damage, TRAN requires that they meet certain safety and performance criteria. One performance criterion is that new truck configurations generate at least 5% less pavement damage (in terms of ESALs per tonne payload) than a specified reference vehicle. Using the widebase steering tire ESAL equations developed in this study, FPInnovations demonstrated that 9-axle tridem-drive log B-trains can have 7,300 kg steering loads and still meet this performance threshold. In May 2020, TRAN published a policy to incorporate this new methodology and, consequently, increased the steering axle loads of 9-axle tridem-drive log B-trains permitted in B.C.

Designing Neighbourhood Collector Streets

mer, 11/04/2020 - 15:49
Designing Neighbourhood Collector Streets
by Swan,J.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5115 - INTERNET


In 2019, Ottawa’s City Council approved the new 'Designing Neighbourhood Collector Streets' document. These up-to date technical guidelines show designers how to balance space within typical street rights-of-way to provide enhanced space for walking and cycling, transit amenities, large trees, and low-impact stormwater management features - all while integrating low vehicle speed design. The guide applies to new collector streets and informs renewal projects. It was developed in consultation with industry, utility, transportation and environmental stakeholders - the primary users of the document. Existing standard street designs mix cyclists with cars on the street, underperform for street trees and environmental quality, and do not meet complete street objectives. The key innovation in this document is the considerable technical depth. A set of nine “pre-vetted” collector street designs and custom design guidance ensures constructability by illustrating complete streets that address key operational needs including below grade utilities, road maintenance, transit and emergency response requirements. These guidelines demonstrate that space can be reallocated to provide safe, comfortable and separated facilities for the most vulnerable street users – pedestrians and cyclists of all ages and abilities and reduce traditionally extensive street pavement widths. They also demonstrate how to provide sufficient space for large trees to flourish, even in Ottawa’s clay soils and buffer them from harsh winter maintenance activities. Broad boulevards can accommodate bioswales to mitigate impacts of increasingly common major storm events. These measures also mitigate heat impacts and sequester carbon at street level, provide habitats for birds and pollinators, and absorb rainwater while contributing to Ottawa’s neighbourhood livability. The “pre-vetted” designs may account for 5-15% increase in capital costs, but with the benefit of reduced costs associated with street design and review, as well as on-going operations and maintenance, and an improved environment for sustainable transportation. Other municipalities can follow a similar process and develop their own guidance to create buildable streets. The weekly stakeholder follow-ups, utility working group sessions, and one-on-one information exchanges addressed issues of technical depth and informed the project team. This document contains solutions to guide technical users and inform citizens when ‘Designing Neighbourhood Collector Streets’.

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