This paper presents a study investigating the accuracy of the two evaluation methods for the assessment of live load capacity factors of bridges as outlined in section 14 of the Canadian Highway Bridge Design Code (CHBDC). The accuracy of the two methods are evaluated, compared, and their shortcomings and strengths are discussed in detail. The results show inconsistency between the general method of evaluation that utilizes load factors in comparison to the mean-load method that applies the statistical coefficients of load, resistance and the method of analysis. A series of numerical parametric studies were conducted to investigate the effect of dead to live load ratios on the accuracy of the results generated through using the code load and resistance factors. The results are further discussed through their application to a major long span case study bridge in the Province of New Brunswick.
The presented work focuses on performance evaluation of concrete beams reinforced in flexure with several different types of rebars. This research takes a holistic approach and is intended to assist engineers, designers, and asset owners with making informed decisions when selecting appropriate reinforcement in a variety of concrete structure applications.
Selection of a suitable type of a corrosion resistant rebar is a complex process and depends on not only initial cost and maintenance but also the overall performance of the structural member. While research examining individual types of advanced reinforcing materials have been conducted in the past, rigorous evaluations of multiple different types of materials tested simultaneously under comparable conditions are rare. Therefore, this research investigated the durability performance of concrete beams reinforced with different types of internal flexural rebars, metal-based and non-metal-based materials, including Fibre Reinforced Polymer (Basalt, Carbon and Glass), Martensitic Micro-Composite Formable Steel, and stainless steel, in addition to the conventional uncoated black steel for comparison purposes. The test specimens represented a bridge parapet and were exposed to identical harsh environmental conditions in a state-of-the-art climate chamber that simulated extended periods of exposure.
In total, twenty-eight reinforced concrete beams were tested for ultimate flexural capacity. All beams were pre-cracked until reaching service conditions and kept loaded with a sustained load of 40% of their ultimate carrying capacity. Twenty-one beams were subjected to severe environmental conditions and subjected to 195 accelerated freeze-thaw cycles (equivalent to five years of real-life exposure) over a period of two months combined with spraying with a 3.5% sodium chloride (NaCl) rich water solutions representing accelerated exposure to traffic spray zones. The duration of each cycle was eight hours with temperature varying from -34°C to +34°C with a relative humidity of 75% for temperatures above +20°C. The remaining seven beams were kept at normal ambient temperature of 22-24°C and served as control specimens for comparison purposes.
The beams were designed to develop similar flexural capacity and their structural performance is descried in detail considering the different nature of the reinforcing materials. The following categories were evaluated:cracking patterns at service loads,cracking patterns at ultimate loads,ultimate flexural capacity and failure modes,corrosion resistance of the rebars,load-deflection behaviour, andductility. A summary matrix table was developed as a guideline to serve in a selection-making process as each reinforcing material offers different advantages that may be suitable for specific conditions.
Traffic signals are becoming more and more complicated nowadays. Traditionally traffic engineers will design the intersection based on traffic count data, field observation, and accident history and warrant analysis. Then drafters will draw the phasing diagram/construction/Traffic Signals for this intersection. Technologists will then implement timing plans and databases based on the drafts. Then the timing plan/database will be handed into signal installers. During all this process, if one chain is broken, then traffic signal safety and operation can be in hazardous situation. The proper application and design of the traffic signal is a key component in improving the safety and efficiency of the intersection. To remove all the uncertainness, a Traffic Signal Head Phasing Diagram will clarify unnecessary confusion.
Signal phasing is the sequence of individual signal phases or combinations of signal phases within a cycle that define the order in which various pedestrian and vehicular movements are assigned the right-of-way. While intersections are becoming more complicated, more functions/phases/movement are needed to adapt to different vehicle and pedestrian requirement, complicated phase sequences and signal head setup come along with it. Following are a few examples, including Dallas Left-Turn Display for Left-Turn Lead-Lag Signal Phasing, Diamond Interchange, Right-Turn vehicle phase overlap, pedestrian phases in a wide intersection that covers two consecutive vehicle phases. Traditional simple signal head design without clear designation may not work well for these complex situations. The solution is to draw a Traffic Signal Head Phasing Diagram/Notation.
The diagram can be drawn in existing traffic signal diagram, just by adding a few more signal head diagrams, with some notations on the side explaining the phase number or overlap number for that signal head. Or a table can be drawn to explain which color in Signal head is driven by which phase or overlap. It sounds like a simple improvement, but for large intersections this process will simplify the guessing process by installers, make engineer/drafter's job much clear, and also make the installers’ job much easier and reduce the risk of wrong connections.
The signal head phasing diagram can avoid unnecessary guesses from traffic professionals, provide a much clearer image of the operation of the controllers and traffic signal indications. One image is worth more than a thousand words!
The design of cost-effective, long-lasting pavements is of high importance in Canada, where daily and seasonal temperature varies significantly. Moreover, the abrupt changes in the global climate and its inverse impacts on transport infrastructures over the last decade require planning for necessary adaptations to mitigate those effects. More research should be conducted to address the potential impacts of climate change on the pavement design. A mechanistic analysis that considers thermomechanical loads could be a tool to study the possibility of variations in frequency or severity of pavement failure due to climate change. Such a model when is fed with site-specific material properties, traffic load, temperature profile, and pavement parameters, would more accurately predict the performance, serviceability and safety requirements. The pavement design may involve identifying tens of parameters, which makes it complex for pavement engineers.
The current study presents a finite element analysis of flexible pavements to evaluate thermal- and traffic-induced stresses for a selected highway cross-section in Canada. The original surface layer is asphalt concrete for which a linear viscoelastic behavior is assumed. Other layers of the flexible pavement were assumed elastic. The annual temperature profile of the studied construction site was obtained from the Long-Term Pavement Performance (LTPP) database. The change in layers stiffness due to air temperature was simulated by considering temperature-dependent material properties. The outcome of the finite element simulation was implemented into the Ontario pavement design guide to evaluate the design life of the studied cross-section. The outcome of this study was also compared with the AASHTO (1993) design procedure to investigate the similarities and discrepancies between the two methods.
The ultimate goal of this project is to develop an online, user-friendly interface to ease the implementation of the pavement design guide in Canada.
Pedestrian comfort is often represented by pedestrian level of service (PLOS). PLOS usually measured using aggregated level of pedestrian volume, speed, and/or density. Very few studies have considered individual pedestrians’ specific gait characteristics to present pedestrian comfort. However, they did not measure individual pedestrians’ comfort real-time basis. The goal of this study was to develop a novel method that can measure individual pedestrians’ comfort real-time basis using pedestrians’ gait characteristics.
More than 60% of rail accidents were reported due to derailments. The most significant causes of derailment accidents are related to defects of track/wayside elements and impacts of environmental factors. Mobile LiDAR (Light Detection and Ranging) System (MLS) is an emerging technology enabling rapid engineering grade mapping and virtual surveying over railway infrastructure. Despite its large potential, MLS has been only used for rail track condition assessment. Its potential for railway asset management has not been exploited yet.
Stopped trucks increase congestion at intersections due to low acceleration rates (Fig. 2) while high volumes of trucks may block all lanes (Fig. 3). Congestion causes traffic delays that lead to economic and environmental costs for trucks and additional frustration for other drivers. Many studies and applications exist for transit signal priority (TSP), but truck signal priority (TkSP) is comparatively unknown.
The City of St Albert in Alberta, a community of 65,000, has an abundance of amenities that attract businesses and residents that seek the “small town” environment, yet offers activities common to larger cities. Stepping into St Albert, these amenities are visible to all. Arts and cultural activities are plentiful. St Albert is called the “Botanical Arts City”. Walking through its downtown core is like strolling in a quaint European town with an underlying modern transportation network. Not surprisingly, as the City grows, it is experiencing “big city” problems such as traffic congestion, delays and accidents.
St Albert has taken steps to develop an ITS “roadmap” to protect this future vision of an inviting, vibrant community, The St Albert Transportation Master Plan (TMP) and the Smart City Master Plan both discussed the steps needed toward a more efficient, safer and “smart city” future. Transportation, innovation, information – all key terms in the future city.
The Nova Scotia Community College (NSCC) conducted a test of the accuracy of the LED Roadway Lighting (LRL) Toolless Sensor Platform (TSP) and its radar sensor for streetlights that detects the movements of vehicles. The NSCC Applied Energy Research Lab (AERLab) evaluated the accuracy of the TSP in a real-world test case on Tower Road, in Halifax, Nova Scotia. NSCC performed 11 sessions of manual data collection and observed 467 vehicular events. These manual observations, along with video recordings, were then compared to the TSP monitor log.
A lack of safe and legal truck parking is considered as a major issue in the freight transportation industry. Hours of service (HOS) and electronic logging device (ELD) mandates, implemented to reduce fatigue, can force drivers to choose between parking illegally or driving longer than allowed. It is important to quantitatively assess the locations and extent of any truck parking deficiencies.
Morrison Hershfield has developed all-new standards for electric vehicle charging station (EVCS) construction projects for the Ministry of Transportation Ontario (MTO) for use in public parking lots. These standard drawings and specifications have been designed with the intent to one day become Ontario Provincial Standard Drawings (OPSDs) and Ontario Provincial Standard Specifications (OPSSes). Ontario has become one of the first jurisdictions to develop standard construction drawings and specifications for the installation of public electric vehicle charging stations and associated infrastructure. The objective of these standards is to assist in the detail design of all future MTO EVCS projects to come.
Long term pavement performance studies and continuous evaluations can help inform better rehabilitation strategies, thus suggesting more innovative rehabilitation designs. This research addressed the performance of asphalt concrete over PCC pavements on four LTPP data sites in the selected wet-freeze climate locations of the US and Canada.
Trip generation analysis plays a vital role in determining the impact of new land use developments. Trips are generally estimated using regionally established trip rates from trip generation data collected over the period of time at specific land uses. However, some regions which do not have their own data usually rely on trip generation data published by other similar regions or on data collected by the Institute of Transportation Engineers (ITE), USA. Over the last 50 years, ITE has already collected data at over 26,000 sites in various parts of the USA and Canada for 173 different types of land uses. As only a small subset of data (~0.5%) is from Canada, there is a question as to whether that data could better represent Canadian sites. As ITE’s Trip Generation Manuals in the hardcopy format do not facilitate viewing or extracting data for specific regions (i.e. country or state) or the ability to aggregate data with local data, practitioners face a number of challenges in using ITE’s data for Canadian sites. To evaluate if data extraction and aggregation have any impact on improving trip generation estimates, data from Canadian and American sites were studied separately in order to analyze the statistical parameters by using the OTISS Pro analysis tools. The analysis revealed that 38% of studies with good data showed significant improvements in terms of fine-tuning standard deviation and regression coefficient (R2) after extracting Canadian sites data. Similarly, about 15% of studies with good data showed improved statistics by aggregating with the American site data. This further helped us to improve trip generation estimates by establishing appropriate trip rates and equations for Canadian sites. Based on this finding, this poster illustrates that by having a way to extract ITE’s data by regions or aggregate with the relevant local data could benefit Canadian practitioners performing qualitative trip generation analyses. It also emphasizes the importance of collecting more regional data.
In-vehicle collision avoidance systems (e.g., automatic braking systems) are designed to protect drivers/passengers and pedestrians in the case of an emergency, but few studies have investigated systems designed to detect potential threats, such as fast approaching vehicles, and warn first responders that they need to take proactive evasive actions to avoid a collision.
Trenching through existing asphalt pavements is a necessity for the installation and maintenance of critical utilities such as water and waste water services in most urban areas. The following will outline observed performance of a recent trench restoration program and provide strategies for decreasing wasted material and improving standards for trench restoration to minimize ground disturbance and material waste in urban residential areas. Drawing on historical information and collected data from pavement condition assessments performed on trenched pavement sections of different ages, the analysis looks to highlight performance characteristics from a lifecycle cost and environmental impact perspective, and relate these findings to pavement management strategies in low traffic, residential areas.
The use of database applications such as gINT to manage site borehole data in geotechnical consulting practice has become common. Such databases reduce the potential cost of future site investigations and allow valuable borehole information to be managed on a broader scale between multiple offices. Such data provides a valuable source for building lithology for 3D site models. When combined with topology, geotechnical shear strength laboratory data (such as shear box or triaxial data), and geotechnical design data an improved 3D conceptual model can be constructed. Such a constructed 3D site model forms a digital twin of the proposed geotechnical design for the real site and can be subjected to analytical simulations to determine if the proposed design meets specifications. Analysis such as slope stability, seepage, and stress/deformation can be performed on the conceptual model based on 2D profile slices or on the full 3D conceptual model.
The movement to performing 3D stability analysis instead of the traditional 2D profile analysis has also heightened the need for fully formed 3D conceptual models of proposed geotechnical designs at sites. 3D slope stability analysis provides the benefit of improved rigor in the calculation of the factor of safety. Calculated 3D factors of safety are higher than 2D factors of safety and allow potential for cost savings on engineering designs that may be over-conservative. These new methodologies are providing advantages in the design of large engineered structures. The additional use of spatial sweeping slope stability analysis such as the multi-plane analysis (MPA) provide maps of factors of safety which further strengthen professional design.
This paper presents an integrated approach to building lithology based on a gINT database and performing 3D spatial slope stability analysis. The new approach leverages the strength of existing borehole databases and provides more rigorous analysis to aid in the design of transportation structures such as embankments, retaining walls, and slopes adjacent to roadways.
This paper presents a state-of-the-practice of truck platooning technology, including policy, regulatory, and technological challenges and opportunities, and an envisioned timeframe for the implementation of the technology. Several demonstration projects on truck platooning conducted in the past have been highlighted, including the demonstration of a truck platooning system on September 14-15, 2017 on I-66 in Virginia, near Centerville. The I-66 demonstration was the most robust demonstration of truck platooning system considering that it was done on a highway in real traffic conditions, one of the busiest and most congested in the nation. Technological advances in automated vehicle technology, including truck platooning, are moving at a rapid pace. However, legislative and regulatory barriers need to be overcome for the widespread application and acceptance of this technology. Also, partnership among various stakeholders is crucial for the success of this technology.
Queen Street and Main Street in the Village of Alton, in the Town of Caledon, ON serves two distinctly different purposes.
For locals and tourists, Main Street and Queen Street serve as the main thoroughfares in a picturesque, historic village. Lined with shops, restaurants, schools, churches, bed and breakfasts, spas and other small businesses; their sidewalks are filled with pedestrians at peak times. For trucks and others passing through, it is a Regional Road that is the fastest way to get to other larger Towns and Cities; and is a primary trucking route. Thus, competing uses provide a challenge in road design.
This situation is not unique, but rather reflective of the typical road configuration in many parts of Ontario, and in Canada in general. The challenge presents itself to ensure pedestrian safety for towns in which their main thoroughfare also serves as a brief slowdown in what is otherwise a high-speed connector road. It has been demonstrated in similar scenarios that reducing regulatory speed limits does not achieve the desired level of speed reduction. Providing supplementary traffic calming features, such as splitter islands, narrowed lane widths, and streetscaping has been used effectively to further lower average speeds and improve pedestrian safety.
Alton is one village that was identified by the Region of Peel as target for traffic calming improvements. At the same time, it was also identified in the Township of Caledon as one of the targets of the “Six Villages Community Improvement Plan”, a revitalization strategy to provide improvements in streetscaping, pedestrian connectivity, signage and other beautification in target villages.
Through extensive design collaboration, stakeholder consultation, community outreach and project delivery, unique streetscaping features were developed that achieved the dual purpose of beautification with traffic calming. The most challenging project constraints included working within a narrow, 15 to 20- meter-wide right of way without acquiring property; environmental impacts; heritage buildings and geometric design considerations.
The project includes a Municipal Class Environmental Assessment (Schedule B), bridge replacement in a Provincially Significant Wetland; vegetated face retaining walls; traffic calming islands with plantings and a gateway feature; decorative streetlighting and pedestrian lighting; new lay-by parking; decorative concrete; and rest areas.
The first construction phase is scheduled to be completed in Spring of 2019. The second phase commenced in the Spring of 2019 and is scheduled to be completed in December of 2019.
As climate change continues to threaten pavement infrastructural performance across the World, the need for sustainable solutions for pavement adaptation cannot be overstated. In Canada, flooding is a prominent climate hazard common to most Canadian provinces and adaptation of pavements to this hazard is desired. Based on previous investigations, concrete pavements are recorded as sustainable, resilient to flood hazards, and proposed to be a good pre-flood strategy. However, design properties need to be given utmost consideration to provide required resilience. This paper takes a design approach to examine the resilience of Jointed Plain Concrete Pavement (JPCP) to flood by modelling the performance of matrices of typical PCC pavement designs in Canada under a Representative Concentration Pathway RCP of 4.5 W/m 2 future precipitation scenario. The AASHTO Pavement ME Design program is used to simulate and predict performance changes under flood scenarios taking the Provinces of Ontario and Manitoba as case studies. In the Ontario study, mean flood damage peaked at 5.99% and 2.39% for collector and arterial JPCP pavement. In the Manitoba study, a total of 27 pavement classes was developed based on typical traffic, slab thickness and subgrade parameters common to the province. From the analysis of all pavement design classes, minimum and maximum damage observed was 0.31% and 3.03% respectively. The performance of the pavement designs classes in terms of flood resilience, service life and cost feasibility were analyzed with respect to traffic and subgrade conditions. Generally, results provided insight into the resilience and adaptive capacity of rigid pavements to climate flood hazards under Canadian climate condition.
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