The geometric design and traffic control measures used by jurisdictions to provide on-road bicycling infrastructure are constantly evolving. Jurisdictions in Canada use guidance such as the 2017 TAC Geometric Design Guidelines (GDG), TAC’s Bikeway Traffic Control Guidelines for Canada (2012), NACTO’s Urban Bikeway Design Guide, Vélo Québec’s Planning and Design for Pedestrians and Cyclists, provincial traffic manuals, and design guidelines from other countries. As the design guidance and provision of modern bicycle treatments is advancing, an important factor in their implementation is the provincial or municipal regulatory framework guiding the right-of-way. This project scans jurisdictions across the country to determine what modern bicycling treatments are being implemented, how these treatments are enabled (or not restricted) by regulation (e.g., municipal by-laws and provincial legislation), and any changes to regulations that have been made to enable the implementation of modern bicycle treatments. While the project will likely focus on provincial laws and regulations, it may also identify those municipal laws or regulations that facilitate implementation of modern bicycle treatments. The purpose of this project is to provide information to jurisdictions to: 1) illustrate where modern bicycle treatments have been implemented in Canada, and 2) reference the regulation or approach that supported the implementation of these treatments.
Cities and towns throughout North America are increasingly investing funds in active transport infrastructure to attract more cyclists, boost economic growth, improve quality of life, and reduce congestion & transportation related greenhouse gas emissions. However, the impacts of this infrastructure on generating cycling demand, and the methods to estimate this latent demand, are not well known. Being able to provide evidence of that latent demand can help support municipalities in their decision making. However, the methods for estimating latent demand for cycling are not well known. A literature review was conducted to provide an overview of the types of tools and methods municipalities can use to predict demand for new active transportation infrastructure. Additionally, a survey was developed and distributed amongst industry and jurisdictional practitioners across Canada, to understand the industry practices focused on latent demand for cycling, and to identify predictors of potential demand for cycling.
The increasing popularity of bicycling as a mode of travel in Canada is leading many jurisdictions to develop new bicycle infrastructure that better meets the safety and mobility needs of bicyclists. However, there is an overall lack of understanding regarding the safety performance of different types of bicycle facilities in the Canadian context. This study characterizes the safety performance of various bicycle infrastructure facilities to help Canadian practitioners evaluate the potential safety performance of new bicycle infrastructure. The report, which is designed as a resource document, is based on a comprehensive literature review, a jurisdictional survey, a series of local and international case studies, and an end user survey. In addition, the document contains a facility selection flowchart that can help practitioners to better inform the selection of a suitable bicycle facility by raising issues to consider in the selection of bicycle facilities and intersection treatments. A key finding of the study is that there are extensive data and knowledge gaps associated with the safety performance of bicycle infrastructure in Canada. These gaps are related to collision and other surrogate safety data, bicycle and pedestrian volume data (exposure data), vehicular traffic volumes by vehicle type, information about the performance of bicycle facilities in winter conditions, and other subjects. There are also significant knowledge gaps regarding the thresholds associated with better safety performance for different factors that impact bicycle infrastructure safety in Canada (e.g. vehicular volume, bicycle volume, proportion of trucks and buses, and frequency of access points). This lack of knowledge was also found to exist beyond Canada.
Road Weather Information Systems (RWIS) provide valuable weather and pavement data used to produce pavement forecasts. Pavement forecasts facilitate efficient winter maintenance operations enabling the right product to be applied at the right time and in the right location, enhancing public safety and minimizing the environmental impact. RWIS stations are expensive to build (~$100,000), forecast, operate and maintain (~$10,000/year). New smaller stations have recently come on the market to supplement full RWIS stations adding value at a reduced price (~$20,000). Wood has successfully demonstrated the value of Virtual RWIS to further densify the network providing additional pavement forecasts at key locations. Seasoned maintenance staff know where their critical locations are that are colder, impacted by warm / cold lake effects, shaded with trees / rock cuts, channel storm winds etc. However, it is hard to know exactly how much the forecasts differ at these locations compared to a typical road section. The Ministry of Transportation, Ontario experiences significant winter conditions along Highway 401 between Kington and Brockville due to winds funneling off Lake Ontario at the throat of the St Lawrence River, proximity to the lake and river, rock cuts, overpasses etc. Wood utilized a mobile RWIS to profile pavement temperatures and conditions continuously along this stretch of highway. Analysis identified the sensitive colder locations and calibrated the differential. Weather forecasting algorithms were developed to accurately forecast pavement conditions in these locations. Wood has been providing Virtual RWIS forecasts at five additional locations along Ontario’s Highway 401 between Kingston and Brockville. Some locations are as close as 6km to an RWIS station where the pavement forecasts freezing and icing conditions not detected at the RWIS station. Once the Virtual RWIS station is calibrated with the mobile RWIS and forecast algorithm, the cost of the station is only for forecasting. Station installation, operation and maintenance are not required, significantly reducing the cost. With the financial challenges, aging population / staff turnover currently impacting all Canadian road authorities, Virtual RWIS provides a cost-effective means to maximize the RWIS data enabling informed decisions to optimize road maintenance operations, road safety and environmental responsibility.
The City of Ottawa Traffic Calming Design Guidelines inform the planning and design of safer community streets, fulfilling the City’s complete streets policies. Previously, traffic calming design in Ottawa was approached from scratch, on a case-by-case basis, reacting to traffic concerns as they arose through retrofits. Today, these guidelines apply not only to retrofits, but also street renewals and new construction with the intent of formalizing low-speed design from the outset and avoid the need for costly retrofits later. The guidelines outline the process, community engagement activities, and features necessary to reduce negative traffic impacts, create attractive environments for vulnerable road users, and meet broader objectives to create livable communities. In April 2019, Ottawa’s City Council approved these new guidelines to walk users through the process to develop traffic calming plans that balance competing objectives and highlight appropriate measures for different applications. They inform the design, application, and evaluation of traffic calming and integrated speed management. The guide also levels the playing field between the public and professionals. It offers the details needed for designers but is illustrated for general consumption to help the public, community and marginalized groups participate meaningfully in the design of safe streets. Application of the new guidelines reduces design and review time by centralizing technical agreements between key stakeholders, introducing a consistent approach to planning and design sensitive to context, and enabling less experienced designers to develop meaningful concepts more rapidly. The results also support the City’s traffic calming retrofit program with a “plug-and-play” planning framework and pre-prepared consultation materials. The project team used historic project examples and more recent traffic calming design experiments as base points in consultations to help refine recommendations with stakeholders in the new guide. For example, details on design options that consider bus service frequency, winter maintenance and emergency response needs are built into the document, addressing Ottawa-specific considerations that could benefit other jurisdictions as well. Calmer streets, developed for and with communities they serve, create environments fostering increased sustainable travel and the resulting social interactions on streets that make neighbourhoods more livable.
The Wildlife Program of the British Columbia Ministry of Transportation and Infrastructure (BCMOTI) is the cornerstone of wildlife protection on British Columbia highways. The standalone program is the point of contact for all BCMOTI’s wildlife-related issues. The program has five main components: (1) monitoring, analysis and evaluation, (2) mitigation, (3) policy and design standards development, (4) research and innovation, and (5) communications, public outreach and stakeholder engagement. The program relies extensively on monitoring and data analysis. With daily wildlife-vehicle collision reporting and a provincial network of over 60 cameras, BCMOTI has been able to confirm the effectiveness of its four wildlife overpasses and many of its over 70 wildlife underpasses for a wide range of wildlife species. The program is developing innovative approaches for reducing wildlife-vehicle collisions, ranging from dog hair as an ungulate repellent and intercept salt feeding as an ungulate attractant, to radar-based wildlife detection systems (WDS) and Artificial Intelligence (AI) driven, species-oriented, variable wavelength bridge lighting. With wildlife exclusion systems costing upwards of $750,000 per kilometre, and WDS systems costing upwards of $2 million dollars each, the program focuses resources where they can be cost-effective. The program draws upon the expertise of BCMOTI’s wildlife, structural, electrical, geotechnical and traffic safety professionals, and a wide range of external professionals and academics. It builds upon the experiences shared by other transportation agencies to develop, test and refine new concepts in wildlife protection. This approach expedites project integration into existing infrastructure and operational practises. The program fosters positive relationships between BCMOTI, the public, First Nations, fish and game associations, and NGO’s. Through Social Media, including Facebook and Twitter, the program is engaging a growing public audience. Weekly blogs provide easily accessible information to satisfy increasing public interest in wildlife protection. Program campaigns have targeted vulnerable road users, including motorcyclists and cyclists. The program supports youth activities, such as the BC Wildlife Federation Wildkidz camps, to raise wildlife awareness among future road users. The Wildlife Program provides an example of how transportation agencies can comprehensively manage and direct wildlife protection initiatives to provide wildlife, road users and taxpayers maximum benefit.
Automated pavement condition surveys have progressed in the past few years. Mainly developed for superior road network needs, such as highway pavements, they are now very often used in the context of surveys and analysis for municipal network pavements. At this level, quality control of the data is of primary importance to obtain accurate and repeatable results that will allow trend detection and fill the needs of municipal pavement managers. Profiler surveys to measure road roughness and laser scan technologies to determine cracking and rutting need a focus adapted to municipal networks. Special cases relative to this domain will be presented (acceleration and deceleration areas of survey vehicles, pedestrian crossings with interblock, railway crossings, speed bumps, surface defects related to snow-removal equipment, lateral obstacles and dirty surfaces). In the absence of adequate quality control of the data, each of these special cases introduces inaccurate global indicators for each segment, such as IRI (ASTM E950) and PCI (ASTM D6433). This paper pinpoints the impact of these special cases in the computed values of the indices. In a few cases, IRI and PCI diverging for as much as 100 % have been noted between data before quality control and after quality control. From these findings, a few approaches to supervise quality control are introduced for the data treatment phase. These approaches are complimentary to equipment specifications prescribed by municipalities.
Over recent years, several Temporary Steel Barrier systems have been successfully crash tested in accordance with the AASHTO Manual for Assessing Safety Hardware and have demonstrated equivalent and in some cases superior performance to Temporary Concrete Barriers which have been traditionally used in Ontario. Temporary Steel Barriers have gained acceptance in Europe, Australia and other areas of North America and the construction industry in Ontario indicated an interest in using them on Ontario highway construction projects. In response to this interest and the demonstrated functional equivalence of temporary steel and concrete barriers, the Ministry of Transportation, Ontario (MTO) sought to standardize the use of temporary steel barrier, which required a major re-write of its temporary barrier specification, shifting to the concept of a Temporary Construction Barrier. The Temporary Construction Barrier concept groups both concrete and steel barriers into four categories, based on their Dynamic Deflection when impacted under MASH TL-3 testing, with a corresponding tender item. Contractors are able to select from all systems that qualify for a given tender item. Most steel barriers require pinning into asphalt, and some have been crash tested with different pin spacings, with more frequent pin spacing resulting in a lower dynamic deflection. For three steel barrier systems, standard drawings were created for multiple pin spacing options which correspond to different Temporary Construction Barrier items. The transition to Temporary Construction Barrier has been well received by the construction industry in Ontario and provides contractors with more flexibility and options for innovation on sites where temporary barrier is required. An added benefit of linking the appropriate tender item with dynamic deflection is higher quality designs as designers are required to consider available space behind barrier to excavations or fixed objects for a staging configuration.
This project involves the analysis and design of a partial Displaced-Left-Turn (DLT) intersection to address road safety and operational concerns at the St. Peters Road intersection on the Trans-Canada Highway in Charlottetown, PEI. As part of this work, PEI Department of Transportation, Infrastructure and Energy analysed numerous intersection improvement and grade separation alternatives, and concluded that an innovative intersection design was necessary. Although promoted by the FHWA, used by several State DOT’s, and recognized in the 2017 TAC Geometric Design Guide for its operational and safety benefits, the application of this innovative configuration is new to Canada. In addition to the significant traffic operational improvements resulting from implementing the DLT, safety benefits will also be realized. When compared to a conventional intersection, using the partial DLT reduces conflict points from 32 to 30. This is a reduction of 2 crossing conflicts typically associated with increased collision severity. Pedestrian-vehicle conflicts are also reduced from 24 to 20. Results from before-after studies in the US suggest a 24% reduction in total crashes and a 19% reduction in fatal and injury crashes following installation of the partial DLT. As the DTL is new to Canada, a cautious approach to the analysis and design was taken. This approach included the application of several analytical methods and tools to assess traffic operations and careful consideration of safety through the use of a senior advisory panel consisting of road safety, human factors and innovative designer experts. Various DTL intersection design configurations were also observed in operation under a variety of environmental and traffic conditions, and interviews with representatives from several State DOT’s were conducted to glean information for the development of best practices and design elements for application in the Canadian context. This project is an excellent example of the application of innovative design solutions to address complex design challenges. It provides a valuable suite of Canadian geometric design, signal, signage, and positive guidance best practices for inclusion in future DLT intersection designs in Canada. In addition, it provides valuable insight on a public education program for the introduction of this new intersection configuration.
The Ontario Ministry of Transportation strives to provide a safe, reliable and efficient transportation system to the travelling public. Constructing safe and durable pavement is critical to achieve this mandate. Ontario has a significant amount of concrete pavement, which includes 849 lane-kms of exposed concrete pavement and 2,187 lane-kms of composite pavement. In 2018, a substantial update to the concrete pavement specification was completed. Significant changes were made to improve the durability of the concrete pavement joints in order to minimize the risk of premature joint deterioration, which can be a safety hazard if the deterioration is severe. Changes to address premature joint deterioration included improved concrete properties and changes to the joint design. The specification implemented the use of longitudinal grooving to replace transverse tinning, which promotes sustainability and safety by reducing hydroplaning and noise levels. Also, the concrete aggregate material specification was updated to increase the insoluble residue content to improve concrete pavement frictional resistance. Furthermore, to improve quality assurance efficiency, smoothness is measured using an Inertial Profiler replacing the use of the California Profilograph. The changes to the concrete pavement specification are critical to ensure a quality product. To date, a few ministry contracts have been constructed using the updated specification. Details of the specification update and impact to the quality are documented in this paper.
The Saskatchewan Ministry of Highways and Infrastructure (SMHI) recently commissioned a Reclaimed Asphalt Pavement (RAP) Management and Application Study to identify and optimize areas of use for RAP materials. With depleting aggregate sources across areas of the province, RAP is considered a valuable recycled material with surplus quantities generated from construction and maintenance activities across the province’s highway network. RAP materials generated from SMHI contracts typically are either: made available to contractors to reincorporate in new hot mix asphalt concrete (with an expectation, but no assurance, that bid prices will be lowered to reflect the value of the RAP; or used as an aggregate substitute within other aspects of the surfacing contract; or retained by SMHI and stockpiled for future maintenance or construction uses (with fluctuation of inventory levels likely depending on current demand). One of the outcomes of the study was the generation of a RAP management plan. The RAP management plan was developed by considering current uses of RAP in Saskatchewan at a consultant, contractor, and agency level; and best practices in other jurisdictions. This paper will present the RAP management and re-incorporation processes developed in the form of an optimization table, and decision flowcharts for use during the design, construction, and operations phases of the roadway.
The Province of British Columbia is committed to eliminating serious injuries and fatalities. One way to reach this goal is through increased use of intelligent transportation technologies. The Road Weather Information Systems (RWIS) combined with variable message signs (VMS) are an innovative safety tool that is being rolled out in British Columbia in areas that experience changing road conditions due to weather events. Weather in B.C. can change rapidly, especially in winter. Adverse weather conditions create an environment in which it is difficult for drivers to navigate safely. RWIS can be utilized to provide travelers with information on current weather and road conditions via electronic variable message signs and reduce the frequency and severity of winter collisions. The Ministry of Transportation and Infrastructure has combined RWISs and VMSs at seven locations on rural highways that experience extreme winter weather conditions and a poor safety performance. Each system comprises of a RWIS connected to two VMSs, one in each travel direction. The RWIS system automatically analyzes weather and road conditions every 15 minutes and an algorithm selects an appropriate sign message to provide real time information to the road users. The safety benefits for implementing a RWIS/VMS were evident with an overall reduction of over 30% in severe winter collisions. The benefits of implementing a RWIS/VMS exceeded the cost, with an overall benefit-cost ratio of 4.8. This indicates that the implementation of RWIS/VMS in British Columbia was an effective investment in improving highway safety. Based on the success of the RWIS/VMS systems in BC, the Ministry has expanded the program to include other ITS technology, such as the LED equipped static signs to alert motorists to specific road conditions, such as the fog warning or icy road sections. The Ministry is continuing to monitor the benefits of the RWIS expansion on our highways but have observed a reduction in serious collisions on the segments where they have been deployed.
General use limestone (GUL) cement is now permitted in the production of all classes of concrete in Canada. Its contribution to reduction in greenhouse gas emissions and sustainable construction is the main driving force for its development globally. However, there has been dearth of information on the effect of GUL on performance of concrete exposed to high concentration of chloride-based salts. Therefore, the aim of this study is to investigate the response, in terms of physico-mechanical properties and microstructural features, of concrete made with GUL without or with fly ash to highly concentrated chloride solutions (NaCl, MgCl2 and CaCl2). A continuous immersion exposure at 5°C was used to promote formation of complex salts (oxychlorides). The results revealed that GUL mixtures exhibited better resistance to de-icing salts due to synergistic physical and chemical actions of limestone in the cementitious matrix. The resistance of concrete exposed to de-icing salts is a function of physical penetrability (magnitude of intruding solution), amount of aluminate in cement and content of portlandite available for chemical reactions in the hydrated paste. The incorporation of high volume fly ash (30%) had a pronounced effect on improving the concrete resistance to damage as reflected by sound mechanical properties and longevity.
Rail transportation systems are increasingly relying on information and communications technologies. Modern industrial control systems which are based on the new communications technologies have replaced the traditional mainframes and obscure protocols which were formerly the backbone of the industry. The cited evolution, however, has enabled a new level of vulnerability through external connectivity, which introduces new risks to public safety and continuous operation of mission critical services. As a means for risk mitigation, cybersecurity has gained an unprecedented level of attention and importance in the context of mission-critical services, in addition to the traditional focus on reliability, availability, maintainability, and safety. In the presented article, the cybersecurity state of affairs for rail transportation systems is investigated and complex security engineering challenges in these mission-critical cyber-physical systems are addressed. The subject of cybersecurity in rail transportation is looked upon from an enterprise-wide point of view, instead of the traditional IT/technological angle. As a result, after a detailed elaboration of the threat vectors and vulnerability scenarios, an interdisciplinary array of mitigation approaches (countermeasures/safeguards) are proposed which are based upon a complete alignment of business aspects and include a multi-front strategy of prevention and recovery-based mitigation through improving system resilience.
It is with increasing frequency that agencies are faced with the impact utility cut installations have on their roadway networks. Excessive utility cuts in pavements are known to cause premature deterioration, pavement weakening, excessive road roughness for the pavement structures, and decrease of pavement asset values. In 2018 the City of Saskatoon (the City) with the assistance of Tetra Tech Canada Inc. (Tetra Tech) completed a study to demonstrate the difference in pavement performance resulting from the presence of utility cuts between 2014 and 2017 on the City’s roadway network. First, roadway condition data (International Roughness Index (IRI) and Pavement Condition Index (PCI)) were assessed for sections with and without utility cuts installed between 2014 and 2017. The features and patterns in the change of IRI and PCI are explored for each City roadway class. Significant differences in reported IRI and PCI were found between pavement with and without utility cuts. Second, the characteristics of utility cuts including the size of the cuts, pavement age, and the IRI and PCI when the cuts were conducted were analyzed. The resultant costs relative to the loss in service life over the pavement life-cycle were determined. Based on pre-utility cut condition instead of pavement age, the pavement performance impacts and potential loss of service resulting from utility cuts were assessed. Finally, linear regression models of IRI and PCI were determined for each roadway class with and without utility cuts. IRI and PCI deterioration curves were developed to evaluate the expenses for utility cuts, loss of service life, pavement rehabilitation cost. Asset value impact matrix were proposed for each roadway class. It is found that the impacts of utility cuts can be quantified, and an associated reduction in roadway asset value and pavement serviceability can be calculated. The information in this study may ultimately be used by the City to assist in determining the costs associated with the utility cuts on their roadway pavement network, and in quantifying the impact of utility cuts on pavement serviceability and the typical loss in pavement asset value.
Permeable pavements are becoming popular in North America especially in the last decade. Permeable pavements are considered as a low impact design and beneficial for best stormwater management practice. Porous Rubber Pavement (PRP) is a comparatively new addition to this type of pavements. PRPs are currently utilized on low traffic roads and pedestrian walkways as surface material. PRPs use as a surface wearing coarse for abating the road noise has been found in few European and Asian countries. The constituents of PRPs are stone aggregates, crumb rubber from recycled tyres, and polyurethane as the binder. As a new pavement material in North America, its performance has not yet been assessed for this climatic condition. Because of its higher permeability (27% to 29% of voids), this material can be highly beneficial for preventing hydroplaning, glare, spray and splash on the road surface during surface runoff. Also, as a result of its flexible nature, it has de-icing capability by deformation of ice on its surface layers. Field pavement performance evaluation was conducted on a parking lot located in Ontario, Canada where PRP was used as surface material. This paper presents some results obtained during these investigations with focus on surface roughness, permeability and surface distress of PRP pavements. Two equipment; SurPRO and Dipstick were employed to investigate pavement roughness in terms of International Roughness Index (IRI). The average IRI of the PRP surface was found to be 10 m/km. The average infiltration rate was found to be 30,836 mm/h. Ravelling (disintegration of material from the surface) was found to be the major surface distress during distress evaluation. Though the PRPs show widespread benefits, there is an opportunity to improve its performance after thorough evaluation, which can make this material a good candidate for the low impact pavement surface. This investigation can be the basis for the future improvement of this material.
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 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.
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-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.