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Using GIS to Analyse Road Light Detection and Ranging (LiDAR) Data for Roadway Settlement and Asset Detection

Fri, 12/22/2017 - 18:33
Using GIS to Analyse Road Light Detection and Ranging (LiDAR) Data for Roadway Settlement and Asset Detection
by Palsat,B; Law,Y; Riessner,M.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5186 - INTERNET


A GIS is classically defined as a system that inputs, stores, processes, analyses, and outputs geographic data. Advancements in processing tools and computing power have not changed the fundamental definition. This poster demonstrates how these elements of GIS, represented by the GIS Lifecycle Loop, can be used to analyze road LiDAR data for roadway settlement detection and asset identification.

Precast Concrete Inlay Panel Installation Method Evaluation (Poster)

Thu, 12/21/2017 - 22:36
Precast Concrete Inlay Panel Installation Method Evaluation (Poster)
by Pickel,D; Tighe,SL; Fung,R; Lee,S; Smith,P; Kazmierowski,T; Snyder,M.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5185 - INTERNET


In recent years, the Ministry of Transportation of Ontario (MTO) has identified a need for a rehabilitation method that: a) has a long service life, b) can be installed in 8-hour construction windows, and c) can be installed reliably. Because of good success in past, PRECAST CONCRETE PANELS were identified as a promising option. Support conditions beneath panels are typically considered to be one of the primary considerations for a well-performing precast slab. During detailed design, three different designs differentiated by their support conditions were produced. A test section was constructed in September 2016 which incorporated each of the three designs. This study considers and evaluates the support conditions based on their construction, including input from the MTO and Dufferin Construction, who constructed the test section.

Investigation of Performance of Superpave Through Mechanistic-Empirical Approach, Field Evaluated Performance, and Laboratory Test Results: A Case Study for Ontario Highways (Poster)

Thu, 12/21/2017 - 22:36
Investigation of Performance of Superpave Through Mechanistic-Empirical Approach, Field Evaluated Performance, and Laboratory Test Results: A Case Study for Ontario Highways (Poster)
by Jannat,GE; Varamini,S; Tighe,SL.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5184 - INTERNET


Although Superpave provides pavement engineers with a method of selecting materials and designing for better performance, the prediction and evaluation of its performance is not integrated in agency pavement management systems (PMS). There is a need to investigate the realistic prediction of the performance of Superpave and how it is used in the pavement management system. The main objective of this research was to compare the distresses predicted by the Mechanistic -Empirical (M-E) approach to the field evaluated performance and Laboratory performance tests.

Field Evaluation of Portland Cement Concrete Pavement Surface Texture and Frictional Properties (Poster)

Thu, 12/21/2017 - 20:33
Field Evaluation of Portland Cement Concrete Pavement Surface Texture and Frictional Properties (Poster)
by Pickel,D; Liu,Q; Wafa,R; Tighe,SL; Fung,R.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5183 - INTERNET


This study looks at the initial surface texture of three PCC pavements constructed in summer/fall of 2016 and compares with skid-resistance performance as measured by the British Pendulum Test (BPT).

Feasibility of Concrete Overlays as a Rehabilitation Strategy on Municipal Roads - City of Hamilton (Poster)

Thu, 12/21/2017 - 20:33
Feasibility of Concrete Overlays as a Rehabilitation Strategy on Municipal Roads - City of Hamilton (Poster)
by Wafa,R; Tighe,SL.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5182 - INTERNET


Residential streets within the City of Hamilton have composite pavements that require a rehabilitation solution. Composite pavements are usually maintained using a mill-and-replace strategy, however, due to joints in the underlying concrete pavement, reflective cracking through the asphalt is very common. Objectives of this study included assessing the feasibility of concrete overlays as a resurfacing/maintenance strategy for the City of Hamilton to use on its municipal streets; developing a construction/implementation guideline for municipalities; and measuring key aspects such as construction cost, construction challenges, pavement durability, and required maintenance cost and frequency.

Comparison of Modern Concrete Pavement Performance Predictions, Thickness Requirements, and Sensitivity to Joint Spacing (Poster)

Thu, 12/21/2017 - 20:33
Comparison of Modern Concrete Pavement Performance Predictions, Thickness Requirements, and Sensitivity to Joint Spacing (Poster)
by Rodden,R; Ferrebee,E; Sullivan,S; Covarrubias,JP; Nantasai,B.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5181 - INTERNET


More than 25 design methods exist for jointed plain concrete pavements (JPCPs) --Many are based on the 1950s AASHO Road Test, including AASHTO 93 and CHAUSEE2 --The prominence of these methods created an expectation for JPCP thicknesses Modern JPCP design methods in North American are: --Founded in mechanistic (M) principles such as finite element analyses and; --Supplemented with empirical (E) calibration to field performance to increase the accuracy of key performance predictions of importance to owners and users, such as: Cracking in slabs, Faulting in joints, and International Roughness Index (IRI). This study extends prior work that compared AASHTO 93, Pavement ME, and StreetPave to illustrate the breadth of design variables considered and the sensitivity of required JPCP thickness to traffic magnitude, the use of dowels, concrete flexural strength, concrete modulus of elasticity, edge support, design reliability, and k-value

Winnipeg's Southwest Transitway - Navigating the P3 Procurement Process

Fri, 12/15/2017 - 21:37
Winnipeg's Southwest Transitway - Navigating the P3 Procurement Process
by Peters,TJ; Taylor,R; Cooper,C.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5180 - INTERNET


Stage 1 of the Southwest Transitway, the initial phase of the City of Winnipeg’s rapid transit network, opened for service in April 2012 providing fast, frequent, reliable service without transfer for most passengers travelling between the southwest part of the City and downtown. The City’s next rapid transit project, Stage 2 of the Southwest Transitway, will extend the transitway southerly to the University of Manitoba. The Southwest Rapid Transitway (Stage 2) and Pembina Highway Underpass Project (SWT2) includes the construction of 7.6 km of exclusive transitway runningway and active transportation paths; six transitway and three rail structures; a noise attenuation wall; two land drainage pump stations; eight rapid transit stations; park and ride facilities; extensive utility and rail relocation works; and reconstruction and widening of the Pembina Highway Underpass. Advancing SWT2 from functional design to construction required the collaboration of engineering specialists, procurement lawyers, and financial advisors. This paper focuses on the engineering aspect of 1) the preparation of the business case and value for money assessment (VFM) for a PPP Canada funding application; 2) preparation and evaluation of the request for qualification (RFQ); 3) preparation and evaluation of the Request for Proposal (RFP), and 4) finalization of the project agreement (PA) for SWT2. The business case and VFM assessment compared a Design, Build, Finance, (operate), and Maintain (P3) procurement against a traditional Design-Bid-Build approach. The engineering aspect for this process included preparation of detailed capital cost estimates. Due to the nature of SWT2, PPP Canada’s Schematic Estimate Guide was not directly applicable (typically used for vertical infrastructure) so a modified costing format was developed. Following confirmation of the P3 procurement method and project funding, an RFQ was issued that prequalified three Proponents. The RFP issued to the Proponents was separated into two main parts: 1) RFP (bidding instructions); and 2) PA (project contract) that detailed the terms of the project delivery. Engineering services provided during the RFP open period included Proponent requests for information, participation in commercially confidential design meetings, modifying the PA to facilitate Proponent innovations, and assistance in the evaluation of technical submissions. The Government of Canada is contributing up to $91.2 million through the PPP Canada Fund while the Province of Manitoba and City of Winnipeg will contribute the balance of the Project costs. At a cost estimate of $467.3 million, this is the largest infrastructure investment undertaken by the City of Winnipeg to date.

Willingness-to-Pay Survey and Modelling for High Occupancy Toll Lanes: Case Study Higway 427, Toronto, Ontario

Fri, 12/15/2017 - 20:37
Willingness-to-Pay Survey and Modelling for High Occupancy Toll Lanes: Case Study Higway 427, Toronto, Ontario
by Afaq,SS; Damodaran,S; Salek,S; Hadayeghi,A.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5179 - INTERNET


High Occupancy Toll (HOT) lanes are considered as one of the traffic management strategies to efficiently utilize the available roadway capacity. In order to understand drivers’ reactions to the planned HOT lane along the Highway 427 corridor in the City of Toronto and estimate the value of time (VOT) and value of reliability (VOR), a web-based stated preference survey was carefully designed and conducted. Using Multinomial Logit (MNL) and Nested Logit (NL) models, the travellers’ willingness-to-pay was derived as the trade-off between travel time saved and toll incurred. The models were further estimated for different market segments.

Wildlife Detection Systems, Highway 3, British Columbia: Real-time warning systems for protecting wildlife and drivers

Fri, 12/15/2017 - 20:37
Wildlife Detection Systems, Highway 3, British Columbia: Real-time warning systems for protecting wildlife and drivers
by Sielecki,L.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5178 - INTERNET


Highway 3 is the most southern trans-provincial highway in British Columbia. It is a key national transportation link for trade, industry and tourism between the Pacific Ocean and the rest of Canada. Along the western slopes of the Rocky Mountains, Highway 3 transects critical wildlife habitat corridors that run between Canada and the United States (Figure 1). Many iconic North American ungulates and carnivores use these corridors to survive. Traffic on Highway 3 represents a serious impediment to the safe movement across the highway for many species of wildlife. Concurrently, the larger wildlife represent a significant potential hazard for drivers (Figure 2). As part of the 2015 Rural Highway Safety and Speed Review conducted by the British Columbia Ministry of Transportation and Infrastructure (BCMoTI), the Highway 3 corridor, between Cranbrook and the Alberta border, was identified as having one of the highest densities of wildlife-vehicle collisions in the province. Presently, the mountainous terrain and extensively fragmented land tenure preclude the construction of wildlife exclusion systems along this corridor. To test alternative technological solutions, to protect both wildlife and drivers, BCMoTI developed specifications for a wildlife detection system (WDS) (Figures 3 and 4) and installed two systems on Highway 3, one near Elko and the other near Sparwood (Figure 5). Despite numerous technological, environmental and operational challenges, the project was delivered on budget and on time. Since going live in 2016, the systems have proven to reduce wildlife-vehicle collisions while maintaining critical wildlife habitat connectivity.

Variable Speed Limit Pilot Project in BC

Fri, 12/15/2017 - 20:37
Variable Speed Limit Pilot Project in BC
by Ludwar,K.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5177 - INTERNET


British Columbia is unique in its challenges. The highways network has more than 46,000 km of roadway and 21 major mountain passes which can be susceptible to rapidly changing road weather conditions. To ensure the safety of the public, BC has been following our BC on the Move, A Ten Year Transportation Plan. One of the key priorities of the plan is to improve highway safety. This plan encourages the use of intelligent transportation technologies to reduce collisions, monitor and manage traffic flows, and provide travellers with timely information. The Ministry recognized that there was a need to develop a system that provided a reliable driving experience during adverse weather conditions to address driver error, distraction and speeding. As part of the commitment to invest in new road safety improvement program, the Ministry designed, constructed and implemented a variable speed limit (VSL) system on 3 corridors in British Columbia that experience rapidly changing weather conditions. These corridors were noted as having severe winter weather conditions, high elevation changes, and a poor road safety performance during winter conditions. The variable speed limit systems were implemented on Highway 5 the Coquihalla, through Snowshed Hill, along Highway 99 between Squamish and Whistler and on Highway 1 from Sicamous to Revelstoke. The VSL system that the Ministry has developed uses road side collected data on surface conditions, weather, and vehicle speed to make a speed limit recommendation. Variable speed limits were implemented to provide a more reliable driving experience by using real time road condition information to calculate speed limits based on current conditions. These pilot systems will improve safety in adverse weather by lowering the speed limits based on conditions. The variable speed limit system has been operational since 2016 and ministry staff have had an opportunity to monitor the changing driver behaviors over the course of this first winter season. Based on the data that has been collected, it is observed drivers are reducing their speeds on the variable speed corridors when a lowered speed limit is posted. Between December 23 and 30, 2016, BC experienced a severe snow event that impacted all 3 corridors as part of the pilot. Analysis of the posted speeds, 85th percentile and precipitation on the corridors showed that drivers responded to the system and lowered their driving speeds.

Tower of Power or Tower of Babel? Making Active Transportation Work in a Big City

Fri, 12/15/2017 - 18:37
Tower of Power or Tower of Babel? Making Active Transportation Work in a Big City
by Richardson,DB.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5176 - INTERNET


The so-called "Mirvish Project", comprised of two 90-storey twin towers located on King Street West in downtown Toronto, represents a unique opportunity to showcase how Active Transportation (AT) can change travel behaviour and public perceptions about "big development" in an urban core. This paper focuses on all of the non-single occupant vehicle (SOV) modes that will be key to the success of this redevelopment project, with a particular emphasis on the tiny amount of motor vehicle parking, but the huge amount of bike parking to compensate. Detailed below is a compelling story of how a 2,000 unit condominium with retail, an art gallery and a College campus can function successfully in a congested environment with virtually no available roadway capacity for motor vehicles. To make it all work, however, over 2,000 dedicated, indoor bike parking spaces are provided, together with an aggressive Travel Demand Management (TDM) Plan plus high capacity transit, carshare, bikeshare and pedestrian facilities. This infill project balances the preservation of designated heritage buildings with stunning architecture by the world-renowned Canadian architect, Frank Gehry. The project has numerous unique design and operational features that are highlighted in this paper and corresponding presentation, to elaborate on how City policies and creative infrastructure can attract residents to cycle for both commuting and recreational purposes. Recent City initiatives to construct cycle tracks along major arterials, as well as to retrofit bike lanes on a multitude of City streets in the vicinity of this mega-project, provide strong incentives for "ordinary folk" to bike to work. A major emphasis is also placed on the pedestrian, who can connect to the City's PATH system for both exercise and utilitarian trips. In conclusion, this paper has broad appeal for both large and small municipalities since it offers valuable insights into how to make a big project on a small footprint really "work". The density is enormous, the cost is staggering, the challenges are daunting but the transportation impacts will be negligible. All of this will be accomplished by placing a significant emphasis on the cycling mode, with help from transit, pedestrian and TDM measures all working in harmony to make a development that is a shining example of high quality, sustainable city building.

This Is a Plug: TAC's Electric Vehicle Sign Package

Thu, 12/14/2017 - 22:37
This Is a Plug: TAC's Electric Vehicle Sign Package
by Beaulieu,D.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5175 - INTERNET


Due to the promotion of sustainable transportation by various government agencies and the private sector, many electric vehicle (EV) signage initiatives were taken in the last few years. One unintended consequence of these good intentions is the design of traffic control devices aimed at EV drivers, but executed without proper consideration to the best practices that govern the field of traffic engineering. As an example, green surfaces, actually reserved for cycling facilities, are frequently used for EV reserved parking. It was in this context that the Transportation Association of Canada’s (TAC) Traffic Operations and Management Standing Committee (TOMSC) undertook the development of traffic control devices aimed at EV drivers. Prior to that, the TAC document Handbook of Recommended Information Sign Symbols for Canada (January 2008) already had a provision for an EV charging station directional sign, but that was an early effort from TOMSC at a time when no major manufacturer even offered an EV for sale in Canada. The design was basically that of the standard gas pump directional sign, but with the letters “EVC” added (for Electric Vehicle Charging). That sign saw little application as the EV community took offense to the fossil fuel analogy. With the new reality of electric mobility front and center, TOMSC set its sights on designing an Electric Vehicle Charging Sign that meets standards as well as the ever changing technological context in which it will be used. To that end, supplementary tab sign options were also developed to stay current with charging technology. Parking regulations at charging facilities must also facilitate rotation and partial charging to offer renewed mobility to EV drivers, and not just privileged parking. Depending on services offered at the facility and the technical aspects of the plug-in vehicle, a full charge can take as little as 30 minutes or as much as 24 hours. Having the option to regulate maximum charging time is thus desirable from an operations standpoint. With this objective in mind, TOMSC also developed an EV Parking Sign to make sure charging facilities are effectively used to charge up EVs, and not just provide a parking place for electric vehicles. This paper and presentation will present in detail TAC’s Electric Vehicle Sign Package, while demonstrating to delegates the process that leads to the inclusion of a traffic control device in the Manual of Uniform Traffic Control Devices for Canada (MUTCDC).

The Evolution of Roundabouts in Newfoundland

Thu, 12/14/2017 - 22:37
The Evolution of Roundabouts in Newfoundland
by MacDonald,M; Allaire,F.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5174 - INTERNET


Roundabouts have become increasingly common on Canada’s roads since the 1990’s, however, Newfoundland and Labrador has been slower to adopt roundabouts as a means of intersection control. Today, roundabouts remain fairly new and somewhat controversial to Newfoundlanders. Major news was made in 2014 when a traffic calming circle was removed on Old Topsail Road in St. John’s. News headlines were referring to the traffic circle as a roundabout and had a damaging effect on the perception of roundabouts in the region. The first modern roundabouts in Newfoundland were constructed at the NLL Recycling’s Robin Hood Bay Waste Management facility. Two single-roundabouts were built to improve site circulation for residential and commercial vehicles entering the facility. While these modern roundabouts being constructed were a significant milestone, since the roundabouts were not constructed on the public road network, it did not contribute significantly to the profile of roundabouts in Newfoundland. It was only 2014 that the Town of Paradise built the first roundabout on the public road network at the intersection of Karwood Drive and Kenmount Road, one of the busiest intersections in Paradise. The resulting traffic impact of the construction of this multi-lane roundabout has acted as a catalyst to roundabout development in the Avalon Peninsula. The roundabout served as an example to surrounding municipalities and residents of the benefits of roundabouts by significantly reducing delay at the congested intersection. As a result, a number single-lane and multi-lane roundabouts have been constructed in the last three years by the City of St. John’s and by private developers. As these new roundabouts on the Avalon Peninsula continue to demonstrate the benefits of roundabouts, their popularity continues to increase and is spreading towards more rural parts of Newfoundland. Many municipalities have requested that preliminary designs be completed at some of their busiest intersections. Some of these include the City of Corner Brook, Town of Grand FallsWindsor, Town of Paradise, Town of Marystown, Town of Torbay and Town of Bay Roberts. With the current economic condition in many Newfoundland communities, the municipal decision-makers are recognizing the fact that roundabouts can create a multitude of benefits, most noteworthy, long term cost savings over constructing other types of intersections. This paper strives to outline the past, present and future of roundabouts in the Province of Newfoundland and Labrador. There are unique challenges that exist in the Province with respect to implementation, acceptance, and education which must be explored and discussed in order to understand the optimal way forward to growing a roundabout program in the Province.

Ten Years of Edmonton's North East Roads Program

Thu, 12/14/2017 - 22:37
Ten Years of Edmonton's North East Roads Program
by Foth,M; Donovan,H.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5173 - INTERNET


In 1999 roadways in four north east Edmonton neighbourhoods began to show significant structural failures earlier than expected. As a result of continued roadway failures a study was carried out by the City of Edmonton Geotechnical Section of Engineering Services in August 2002 to identify the issue and its extent. The original study and a successive study carried out by Golder Associates in 2005 revealed that water was softening the subgrade soils causing these failures to occur. The issues include subgrade soils that were susceptible to water softening, additional surface drainage from private sump pumps and poor subgrade drainage. With this information, the City developed several options for remediation of the failed roadways as well as to reduce the availability of water to the subgrade soils. The plan chosen involved full reconstruction of the roadway and installation of edge (periphery) drains. The new roadway cross section consisted of, non-woven geotextile, installation of 200mm diameter perforated PVC lateral drains along curbs on both sides of the road connected to the stormwater system, recycled 63mm granular base, geogrid, virgin granular base course and asphalt concrete. In 2006 the first project with sub-drains was constructed and consisted of approximately 550m of roadway with a cost of approximately $1.5 million. Over the past ten years the treatment plan has shown to be working to address the issues and the City currently has two annual contracts each completing approximately 1,300 to 1,400m of roadway reconstruction at a cost of approximately $3.0 million dollars per year. In the past ten years the City has completed approximately 14 km of roadways within the neighbourhoods that were part of the original study and has locations for the next three years in place. Many construction techniques have been learned including how to work around utilities, development of drain wells and maintaining access for residents. Late 2016 additional neighbourhoods were starting to show distresses similar to those reviewed in the study. As such, in 2017 neighbourhoods outside of the original study area will be reconstructed and others that are starting to show earlier signs of similar failures will be monitored regularly through visual inspections and structural testing.

Survey of Current Asphalt Binder Extraction and Recovery Practices

Wed, 12/13/2017 - 21:37
Survey of Current Asphalt Binder Extraction and Recovery Practices
by Mikhailenko,P; Baaj,H.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5172 - INTERNET


In the context of a literature study for the Ministry of Transportation of Ontario, a survey was conducted on asphalt binder extraction and recovery, with government agencies and research laboratories in the United States, Canada and Europe participating, receiving 40 responses. Respondents from United States Departments of Transportation (DOTs) comprised the majority of responses. The survey covered three categories of test evaluation: apparatus type, performance and safety. The Centrifuge was found to be the most common extraction method, the Rotary Evaporator was found to be the most common method of recovery and Trichloroethylene was found to be the most common solvent. Only two respondents mentioned using bio-sourced solvents. The most common uses for extraction and recovery were for the analysis of RAP binder and the determination of binder content. The determination of binder content was found to be consistent by all of the respondents. About half of the respondents found that the recovered binder properties were modified during extraction and recovery process in a significant way while the others found issues with binder aging and solvent remaining in the binder. Concerns were raised about the testing of RAP and PMA binders, in terms of difficulty in breaking them down. The average extraction and recovery took around 5 hours. Operator safety concerns focused mostly on volatiles and handling at hot temperatures, while environmental safety concerns focused on toxic chemicals and waste disposal. A number of recommendations were provided by the respondents for improving the test methods.

Surrogate Safety and Network Screening: Modelling Crash Frequency Using GPS Data and Latent Gaussian Models

Wed, 12/13/2017 - 21:37
Surrogate Safety and Network Screening: Modelling Crash Frequency Using GPS Data and Latent Gaussian Models
by Stipancic,J; Miranda-Moreno,L; Saunier,N; Labbe,A.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5171 - INTERNET


Improving road safety requires two steps of network screening and site diagnosis, which both require safety to be objectively quantified. In the screening phase, sites are identified and prioritized to maximize the efficiency of implemented countermeasures. Network screening methods commonly adopt regression techniques to estimate the expected number of crashes at sites across the network. Most existing techniques use crash-based ranking criteria which are subject to errors and omissions in collision databases, require long collection periods, and are reactive. GPS-enabled smartphones can collect reliable and spatio-temporally rich naturalistic driving data from regular drivers using an inexpensive, simple, and user-friendly tool that eliminates the need for external sensors. To date, very few studies have analyzed large volumes of smartphone GPS probe vehicle data or have considered advanced modelling techniques for screening in large road networks. The purpose of this paper is to develop a crash frequency model that incorporates surrogate safety measures (SSMs) extracted from the smartphones of regular drivers as predictive variables. After processing GPS data collected in Quebec City, Canada, several SSMs including vehicle manoeuvres (hard braking) and measures of traffic flow (congestion, average speed, and speed variation) were extracted. A Latent Gaussian Spatial Model was estimated using the INLA technique. Results showed that while negative binomial models outperformed Poisson models, the greatest improvement in model fit was achieved through a spatial model. In general, the relationships between SSMs and crash frequency established in previous studies were supported by the modelling results. Future work will include expanding the crash model to the entire Quebec City road network, comparing models estimated using INLA to those estimated using a traditional MCMC simulation, and incorporating collision severity estimation. The ability to screen the network based only on SSMs presents a substantial contribution to the field of road safety, and works towards the elimination of crash data in safety evaluation and monitoring.

Some Recent Environmental Pavement Technologies - Fact or Fiction

Wed, 12/13/2017 - 21:37
Some Recent Environmental Pavement Technologies - Fact or Fiction
by Johnston,A; Riessner,M; Luo,C.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5170 - INTERNET


The roadbuilding industry has been working towards environmental stewardship in many aspects of pavement construction. As an example, almost 100% of reclaimed asphalt pavement is recycled and used in pavement construction. In fact the amount of recycled asphalt pavement used exceeds that of glass, paper, aluminum and plastic combined. Warm mix asphalt represents another advancement with significant environmental advantages, such as reduced fossil fuel costs and less emissions. More recently, two pavement technologies have come to the forefront; permeable pavements and solar pavements. Permeable pavements offer an enhanced method for managing stormwater. These pavements, generally used for parking lots or other low traffic applications, allow stormwater to drain through the pavement surface into a stone recharge bed (or reservoir) and infiltrate into the soils below the pavement. The surface of a permeable pavement can be specially designed asphalt concrete or Portland cement concrete, or permeable pavers. Advantages include purifying stormwater runoff, and replenishing water tables and aquifers rather than forcing rainfall into storm sewers. Solar pavements are even a more recent environmental development. Solar pavements (or surfacing) is a modular system of specially engineered solar panels that can be walked and driven upon. In some cases the panels contain LED lights to create lines and signage without paint. They can contain heating elements to prevent snow and ice accumulation. The Netherlands built the first solar road, a bike path, in 2014. France announced a bolder move recently that over the next five years, it plans to install 1,000 kilometres of solar roads. Installations in North America are likely “just around the corner”. This paper will have the objective of providing a fair, but critical review of these two pavement technologies, specific to the Canadian context. There can be no denying that these innovations have a significant environmental upside; but does that upside come at a cost, a cost that may or may not make good sense?

Solutions to Driver Errors at Multi-Lane Roundabouts

Wed, 12/13/2017 - 20:36
Solutions to Driver Errors at Multi-Lane Roundabouts
by Weber,P; Tanaka,K; Henderson,B.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5169 - INTERNET


It is acknowledged that multi-lane roundabouts result in more collisions between users than single-lane roundabouts. Much of this has to do with the fact that multi-lane roundabouts handle more traffic. The safety performance of multi-lane roundabouts should therefore be compared to signalized intersections that accommodate similar traffic flows. However recent data in the United States and Canada are showing that collision frequency at multi-lane roundabouts is often higher than expected, and sometimes higher than the prior signalized intersection. This trend is worrisome given that roundabouts are often constructed as a means of increasing safety. The good news is that fatal and injury crashes are almost always reduced with roundabouts, even if property-damage-only crashes are not. The bad news is that often only total crashes are reported by a road agency or picked up on by the public. This is starting to foster the impression that multi-lane roundabouts are not all that safe. Multi-lane roundabouts have tremendous safety potential. Unlike single-lane roundabouts, which are applicable at lower-volume locations, multi-lane roundabouts can all but eliminate the high-speed angle crashes that injure and kill motorists, cyclists and pedestrians at large signalized intersections. But unless the trend toward higher-than-expected collision frequency is reduced, the future of multi-lane roundabouts may be in doubt.

Roughness Degradation Models of Flexible Pavements Subjected to Seasonal Frost Action

Wed, 12/13/2017 - 19:35
Roughness Degradation Models of Flexible Pavements Subjected to Seasonal Frost Action
by Sylvestre,O; Bilodeau,JP; Doré,G.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5168 - INTERNET


In cold regions, flexible pavements are constantly submitted to the effects of repeated traffic loads combined with the climate effect. The frost heave of the subgrade soils due to formation of ice segregation is among the main mechanism involved in the high deterioration rate of flexible pavement. This paper presents developments of flexible pavement damage models, developed through a multiple linear regression (MLR) analysis, associating long-term roughness performance to degradation mechanisms, such as, among others, frost heave. Those models would be essential to assess the advantages or consequences to have a frost heave lower, equal or higher than the allowable threshold values established by the Ministry of Transportation of Quebec (MTQ) according to the roads functional classification. One of the models developed uses the cracking performance index as a direct quantification of cracking and the other one uses indirect cracking quantification using thickness and age of pavement. This research illustrates that a notable increase in long-term IRI deterioration rate of pavement is usually caused by frost heave, variable subgrade soil and traffic. Obtaining the flexible pavement damage models with the various degradation mechanisms will help to predict and reduce the residual distortions that affect the structural and functional capacities of cold region’s road network.

Rising to the Challenge: From Concept through Construction Repairs of the Existing Taylor Rd. (Callender Hamilton Through Truss Type) Bridge Grand Falls-Windsor, NL

Tue, 12/12/2017 - 22:13
Rising to the Challenge: From Concept through Construction Repairs of the Existing Taylor Rd. (Callender Hamilton Through Truss Type) Bridge Grand Falls-Windsor, NL
by Pottie,W.
2017.
TAC 2017: Investing in Transportation: Building Canada's Economy - - 2017 Conference and Exhibition of the Transportation Association of Canada.
CA6 ARH_10 2017A5167 - INTERNET


The Callender Hamilton through truss bridge crosses the Exploits River in Grand Falls-Windsor, NL, and serves as a vital link for both industry and the public in the area. In January 2016, a heavy vehicle struck the bridge’s south portal strut and caused severe damage to several non-redundant truss top chord and diagonal members along with several other secondary members. Harbourside Engineering Consultants (HEC) were retained by Newfoundland and Labrador Department of Transportation and Works (NLDTW) to complete a repair design and procedure, with the mandate being to restore the existing structure’s full inherent capacity while minimizing design time, bridge closure time, and overall project costs. The project involved a number of challenges requiring an innovative and unique solution. Because the damaged elements included non-redundant members, the loads in these members had to be relieved by introducing an alternate load path prior to their replacement. Due to the site geometry, specifically a near-vertical cliff over 20m high directly in front of both abutments, along with cost and schedule restraints, standard repair methods were conceptualized but ultimately deemed impractical. The solution came in the form of an innovative temporary adjustable-length diagonal jacking strut design, whereby jacking struts were strategically located within the existing truss to create an alternate load path which bypassed the damaged members. A complex jacking system within the struts, including a creative sleeve-type slider system to maintain stability of the strut during the jacking procedure, was developed to maintain bridge geometry and relieve load in the existing damaged members prior to their replacement. A structural evaluation of the bridge superstructure was also part of HEC’s scope of work as the live load carrying capacity of the bridge was never verified since its construction in the 1960’s. The structural evaluation concluded that a number of structural elements did not meet Canadian Highway Bridge Design Code (CHBDC) CAN/CSA S6-14 requirements. As such, a combination of bolt material testing (to verify the existing bolt strength properties) and posting axle limits were recommended for the bridge following completion of the vehicle collision repairs. In addition to completing the detailed repair design and procedures, HEC provided an on-site Engineer for supervision and direction during all phases of the repair works, including the critical jacking sequences. The project was ultimately a success, being completed safely, on budget, and just marginally over schedule while meeting the main objective: reinstating the inherent load carrying capacity of the structure.

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