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

Mon, 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

Mon, 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

Mon, 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™

Mon, 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

Fri, 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

Fri, 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

Fri, 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

Wed, 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

Wed, 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

Wed, 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

Wed, 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

Wed, 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

Wed, 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’.

Design and Construction of Extradosed Bridges in Cold Temperature and Seismic Zones

Wed, 11/04/2020 - 15:28
Design and Construction of Extradosed Bridges in Cold Temperature and Seismic Zones
by Schueller,M.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5114 - INTERNET


Extradosed bridges are often described as a cross of a conventional prestressed concrete bridge and a traditional cable-stayed bridge because most extradosed bridges built combine a prestressed concrete superstructure with stay-cable technologies. However, this simple definition does not capture the various possible structural systems and different materials that can be found and used for extradosed bridges. Extradosed bridge technology is much more than a prestressed concrete girder with external tendons. The Deh Cho Bridge in the Northwest Territories and the Canal Lachine Bridge in Montréal are two Canadian extradosed bridges featuring steel superstructures with slender composite concrete decks using full-depth precast panels. Although both bridges are very different, they share one important constraint which governed the design of their superstructures: Both bridges are located in regions with prolonged extreme cold winter periods. Below zero temperature extending over a longer period can be a major hindrance when erecting long bridges with conventional concrete superstructures. On the contrary, steel superstructures are light and can be quickly erected, even at far below zero temperatures without heating and hording given that field welding is avoided. To avoid delays along the critical path in the erection of major superstructures in extreme cold temperature zones, designers should consider erection schemes which make best use of short warm weather periods and reduce negative impacts related to harsh weather conditions as best as possible. To achieve this design objective, it is recommended that proven construction schemes and technologies are investigated in the early design phase of the superstructure design before superstructure type, cross sections, and materials are selected. This holistic approach goes far beyond what commonly is described as Accelerated Bridge Construction (ABC) because the goal here is a tailored superstructure design for the specific location of the structure including the preferences of fabricator and contractor. The paper will present the specific design features and construction methods selected for the Deh Cho Bridge and the Canal Lachine Bridge. Structural details and achieved synergy effects by combining superstructure design and erection engineering will be discussed. Further, the advantages of modern light-weight construction principles over traditional girder superstructure types will be emphasized to demonstrate their advantages when building bridges in seismic zones.

Cracking and Rutting Performance Evaluation of Asphalt Mixes for Moving Towards a Balanced Mix Design - A Pilot Study

Tue, 11/03/2020 - 22:19
Cracking and Rutting Performance Evaluation of Asphalt Mixes for Moving Towards a Balanced Mix Design - A Pilot Study
by Rizk,M; Ghazy,A; Ahammed,MA; Shalaby,A; Liske,T; Tran,T; Kibbins,B.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5113 - INTERNET


The balanced mix design approach considers a matrix of volumetric properties as well as cracking and rutting performance in the selection of asphalt mix constituents. In Manitoba, asphalt mix design and mix acceptance are becoming more and more complex with the increasing uses of recycled materials, binder additives/modifiers, and multiple warm-mix asphalt technologies. The objective of this study is to conduct a pilot performance-testing program to evaluate the asphalt mixes, for potential field performance in terms of cracking and rutting to optimize asphalt mix constituents for moving towards the balanced mix design. Hot-mix asphalt and warm-mix asphalt laboratory compacted specimens along with field compacted specimens were assessed for cracking and rutting performance using the Illinois Flexibility Index Test and Hamburg Wheel-Tracking Test, respectively. Results showed that warm-mix asphalt mixtures have a lower cracking potential than hot-mix asphalt mixtures. The well-compacted field mixtures displayed a low rutting potential. Low mixing/compacting temperatures using WMA additives, proper voids in mineral aggregate content, and adequate field compaction (low air voids) were found to be viable candidates for an effective balanced mix design approach.

County Road 20 One-Way Cycle Track

Tue, 11/03/2020 - 21:12
County Road 20 One-Way Cycle Track
by Wilson,K.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5112 - INTERNET


Working together with local municipalities and community groups, the County of Essex has spearheaded a project to improve conditions for pedestrians and cyclists in this rural Southwestern Ontario region to help more people recognize active transportation as a way to move from place to place. The County Wide Active Transportation Study (CWATS) focuses on reducing dependence on single-occupant vehicles by encouraging modal integration and accessibility within the transportation network. The One-Way Cycle Track project involves the development of a well-designed, purpose-built facility and has created opportunities for safe, efficient and convenient cycling and walking facilities where it was needed most. The construction of a 6km raised cycle track on both sides of County Road 20, through the municipality of Leamington and Town of Kingsville was completed in 2019. This cycle track is a bicycle facility adjacent to and vertically separated from the roadway and provides facilities for cyclists traveling in each direction to ensure continuity and connectivity. It is designated for exclusive use by cyclists and is distinct from the sidewalk. The facility demonstrates how to apply the OTM Book 18 facility selection process and understanding specific user needs, e.g. children and migrant workers. The project was delivered through an innovating funding partnership between an upper and lower-tier municipality. This is just one segment of an approx. 800km active network. The County established an Active Transportation Steering Committee and learned that success depends on effective communication and coordination between partners and stakeholders. The County owes much of its success to the strong support Council has given to sustainable planning and transportation initiatives. The CWATS program promotes healthy, active and sustainable lifestyles while recognizing the importance connected trails play in supporting tourism and residential development. This innovative project demonstrates social, economic and environmental benefits through the availability of safe infrastructure accommodating utilitarian to recreational users. Additionally, this improved facility encourages continued growth for our cycling tourism industry along Essex County’s wine route which in turn contributes to a healthy, livable community through integrated planning. This project implementation and success is transferable to other municipalities by showcasing successes of collaboration.

Cohesive Clays for Construction and Stabilization of Unpaved Roads

Tue, 11/03/2020 - 20:39
Cohesive Clays for Construction and Stabilization of Unpaved Roads
by Mumin,H.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5111 - INTERNET


Cohesive clays and organic catalysts are tested and used for the construction and stabilization of the wearing surface of unpaved haulage and high-maintenance municipal roads in Manitoba. The process requires a typical A-base aggregate with good particle size distribution and a very high (>25%) fines and clay content. For this application, the inherent electronic bonding potential of natural reactive clay is harnessed to maximize clay to clay mineral bonding while limiting clay to water bonding and water ingress. Catalysts are used to promote densification, clay bonding with cationic polymers (present in natural soils and in the catalyst), and water egress. The result is a strong, semi-permanent clay cemented matrix that effectively bonds the aggregate mix. This produces a dense road surface with high bearing strength, superior durability, excellent road functionality, and low maintenance requirements. Only natural materials are used with no deletrious environmental impacts, and dust is reduced to a minimal level. An added benefit is the significant reduction in the use of high-quality aggregates, extending the life of known resources. Both high-traffic heavy haul roads and municipal roads have been construction and monitored in the Brandon region over the past five years, with no indication yet when the road surfaces will require a significant upgrading or reconstruction. This paper discusses the electronic bonding properties of clays, how and why the process works, the types of materials that can be used, road performance to date, and some of the applications where these types of roads can be very beneficial in terms of performance, cost and environmental impact.

Climate Change Implications for Pervious Concrete Pavement

Tue, 11/03/2020 - 20:12
Climate Change Implications for Pervious Concrete Pavement
by Shafiee,M; Maadani,O; Murphy,E.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5110 - INTERNET


Future changes in precipitation and extreme flood events represent risks for urban infrastructures in Canada. Pervious concrete pavements (PCP) are normally designed to reduce the runoff water and avoid urban flooding as a stormwater management solution. As a result, it is important to adapt PCP design to changing climate by considering site-specific projected storm intensities and durations. In this study, data from simulated Intensity Duration Frequency (IDF) curves were incorporated in PerviousPave software to evaluate the PCP’s hydrological and structural performance. Projections of future changes in storm intensity and their influence on PCP performance highlighted the need for remedial measures and adaptation policies.

Climate Change and Asphalt Binder Selection: Resilient Roads of the Future

Tue, 11/03/2020 - 19:55
Climate Change and Asphalt Binder Selection: Resilient Roads of the Future
by Shafiee,M; Maadani,O; Murphy,E.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5109 - INTERNET


Adapting flexible pavements systems to the impact of climate change is a challenge in Canada. It is well-known that increasing temperatures and more frequent extreme heat events represent risks for the flexible pavements. These vulnerabilities may put additional pressure on Canadian transportation infrastructure and economy, as weather begins to deviate more and more from historic temperatures. Selecting suitable Performance Graded (PG) asphalt binders for pavement construction heavily depends on temperature conditions at the site. Hence, the goal of this research paper is to evaluate the impact of climate change on PG selection for several Canadian cities based on different Representative Concentration Pathway (RCP) scenarios. In this study, projected temperature from ANUSPLIN datasets were used to obtain the necessary climatic parameters defined in the SUPERPAVE specifications. Projections of future PG changes highlighted the need for climate change adaptation policies and action sets in Canada.

Changes in Asphalt Binder Grade Due to Climate Change in Canada

Tue, 11/03/2020 - 19:39
Changes in Asphalt Binder Grade Due to Climate Change in Canada
by Swarna,S; Hossain,K.
2020.
Transportation Association of Canada 2020 Conference and Exhibition - The Journey to Safer Roads.
CA6 ARH_10 2020A5108 - INTERNET


In recent years, average temperatures in Canada have been continuously increasing, owing to changes in the global climate. This can be attributed to a surge in the concentration of greenhouse gases in the atmosphere. Climate scientists predict the trend to further aggravate in the near future. Pavement performance models show that changing climate will result in accelerated pavement deterioration. To mitigate pavement deterioration, various adaptation strategies have been suggested in the recent literature. One of these adaptation strategies is upgrading the superpave asphalt binder grade. It is well known that asphalt binder is highly sensitive to climate factors such as temperature and percent sunshine. Hence, reviewing asphalt binder grade is a vital step and that can help decelerate pavement deterioration. The goal of this work is to determine new asphalt binder grades in Canada based on the projected climate data. To achieve this goal, the analysis was carried out in four phases. In the first phase, statistically downscaled climate change models were gathered from the Climate Change model database. Then in the second phase, hourly temperatures were estimated using existing hourly data and state of the art estimation models for each day throughout the design period. Later in the third phase, using the estimated hourly temperature, average seven-day maximum pavement temperature and minimum pavement temperature are determined. Lastly, high-temperature grade (XX) and low temperature grade (YY) of an asphalt binder (PG XX – YY) are estimated using the average seven-day maximum and minimum pavement temperature respectively and tabulated in an easy-to-use format for application by the transportation agencies in Canada. Results reiterate the necessity of upgrading the asphalt binder grade in various provinces of Canada.

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