Gardiner Expressway Research Articles

Skateboarding, gentle activism, and the animation of public space: CITE – A Celebration of Skateboard Arts and Culture at The Bentway

ABSTRACT This paper examines the interplay of leisure, activism and the animation of public space by exploring CITE – A Celebration of Skateboard Arts and Culture, an art installation and pop-up skate park featuring skateable sculptures constructed in commemoration of Toronto skateboarder Justin Bokma. CITE, which took place in the summer of 2018, deliberately transformed The Bentway, a new public space and programming platform in Toronto which has transformed the underside of the Gardiner Expressway into a gathering place for city inhabitants, into a temporary destination where skateboarders engaged in activist, educational, and arts and cultural practices to situate the act of skateboarding within the broader context of urban placemaking. Drawing on a variety of empirical materials (e.g., interviews, videos, social media, promotional materials, press releases, observations), this case study seeks to understand how so-called ‘gentle activism’ animates public space and advances inclusive placemaking. Findings show that, through gentle activism, CITE underscored (1) the salience of arts and aesthetics in advocating for skateboarding, (2) inclusivity of programming to facilitate interaction between skateboarders and the non-skateboarding public, (3) the utilisation of programming to amplify the activist message, and (4) intentional efforts to change perceptions of skateboarders. The case reveals a successful alternative to defensive placemaking efforts.

“Common Sense Geography” and the Elected Official: Technical Evidence and Conceptions of ‘Trust’ in Toronto’s Gardiner Expressway Decision

In fields such as Sociology and Political Science, there have been, over the course of three decades, attempts to engage elected officials in “Evidence-Based Decision-Making”. Evidence is generally conceived as “expert” advice provided to politicians. A question that has gained more centrality in recent years is “why do elected officials not trust expert opinion or technical evidence?” and the answer to this question has been sought in historical or general terms (e.g. Irwin 2006; Weiss et al. 2008; Kraft et al. 2015). Here I will propose an alternative question: “when politicians exhibit a lack of trust in expert advice, how is such skepticism publicly accounted for?” I will examine this question by utilizing a case study ethnographic approach to the City of Toronto’s controversial decision to endorse the Hybrid alternative for the Gardiner expressway. By doing so, I intend to show that knowledge controversies are not inherently a form of deficiency on the part of the elected official – that they are ignorant to the implications of evidence – but rather the standard by which elected officials and appointed experts review and understand evidence can lead to very different (although both reasonably ‘correct’) conclusions.

Assessing rear-end collision risk of cars and heavy vehicles on freeways using a surrogate safety measure

This study analyzes rear-end collision risk of cars and heavy vehicles on freeways using a surrogate safety measure. The crash potential index (CPI) was modified to reflect driver’s reaction time and estimated by types of lead and following vehicles (car or heavy vehicle). CPIs were estimated using the individual vehicle trajectory data from a segment of the US-101 freeway in Los Angeles, U.S.A. It was found that the CPI was generally higher for the following heavy vehicle than the following car due to heavy vehicle’s lower braking capability. This study also validates the CPI using the simulated traffic data which replicate the observed traffic conditions a few minutes before the crash time upstream and downstream of the crash locations. The observed data were obtained from crash records and loop detectors on a section of the Gardiner Expressway in Toronto, Canada. The result shows that the values of CPI were consistently higher during the traffic conditions immediately before the crash time (crash case) than the normal traffic conditions (non-crash case). This demonstrates that the CPI can be used to capture rear-end collision risk during car-following maneuver on freeways. The result also shows that rear-end collision risk is lower for heavy vehicles than cars in the crash case due to their shorter reaction time and lower speed when spacing is shorter. Thus, it is important to reflect the differences in driver behavior and vehicle performance characteristics between cars and heavy vehicles in estimating surrogate safety measures. Lastly, it was found that the CPI-based crash prediction model can correctly identify the crash and non-crash cases at higher accuracy than the other crash prediction models based on detectors.

“Passive Combatants”: Online Discourses of the “Tamil Woman” and the 2009 Gardiner Expressway Occupation

“Passive Combatants”Online Discourses of the “Tamil Woman” and the 2009 Gardiner Expressway Occupation Daphne Jeyapal (bio) Triggered by a particularly gory day in Sri Lanka’s conflict, around five thousand protesters in Toronto made their way onto the Gardiner Expressway and shut down six lanes of traffic for approximately six hours on Sunday, May 10, 2009—Mother’s Day.1 The Gardiner occupation was one part of the large-scale mobilization of hundreds of thousands of Tamils around the world in response to the culmination of decades of political repression, subjugation, and structural genocide. While some celebrated the Gardiner occupation as an innovative transnational protest practice, justified as an understandable response after months of protesters being ignored, most commentators condemned the act as “dangerous,” “unlawful,” and “the wrong way to protest.” Online discussions critiqued women’s presence at the protest’s frontlines as “human shields,” initiating debates on the agency of racialized women in activism. Within broader feminist debates about online communication’s potential to transform women’s social and cultural experiences, in this paper I explore how the virtual organizes, alters, confronts, and is shaped by gender and race relations. Discourses of the Gardiner protest that highlight the racial divide constructing women’s resistance in “real” space parallel representations of women’s resistance in virtual space. The sociopolitical space of activism within “real” and virtual realities are still grounded in race politics that are mediated by the nation-state. Inderpal Grewal and Caren Kaplan’s insightful definition of transnational feminism helps to highlight that it is through social practices of border crossing—in this case, through places, platforms, and realities—that power relations between and within feminisms are uncovered.2 Feminists who continue to struggle with issues of privilege and difference [End Page 152] in online spaces must emphasize a critique of the dominant “gaze” that has “whitened our technological stories.”3 With such a critique in mind, I examine a combination of online and offline discourse to explore what happens when an act of transnational protest by racialized women moves from offline-and-local to online-and-(trans) nationally networked. Information and communication technologies (ICT) were central in this social movement. Through ICTs the Tamil diaspora came to know, engage with, challenge, and organize against their oppression across borders. As media reports and key informants from my research echoed, the incredible global mobilization of 2009 would not have been possible without the digitization of the unfolding conflict in Sri Lanka, or the virtual connection of a transnational network of activists and community members. In Canada, Twitter and texts were used to organize impromptu protests, including the mass occupation on the Gardiner Expressway. Mainstream media reported police discomfort over the community’s use of ICTs to mobilize. Journalists spoke of needing to be engaged with Tamil online networks and news sources because they provided comprehensive reports from around the globe. These narratives suggest that as the movement unfolded in “real” space, it was simultaneously constructed and negotiated in cyberspace. However, the promise of technology resides within a paradox: technologies can enable marginalized groups, but they can also exacerbate marginalization. In the digital age, when racialized women digitize their resistance across borders of lived and virtual realities, examining the conditions underlying representations of their activism is critical: our revolutions are tweeted, battled on Facebook, and borne witness to on YouTube. The politics of gender and race underscore them all. Building upon growing scholarship on the agency and resistance of racialized women around the world,4 and drawing upon the contributions of critical race and postcolonial scholars,5 this essay highlights the representational politics of the racialized woman activist—the composite “Third World woman” in the West6—who engages in radical, transnational protest practices against national conflicts. Since “womanhood” is constructed through gender, ethnic, and racial divisions within the nation, protest provides a powerful site to unpack how the essentialized role of women frames them not only as a nation’s biological and symbolic reproducers but also as its ideological reproducers.7 Women’s function as an assemblage of ethnic and racial collectivities and difference is amplified through the antagonism of protest across “real” and cyber space. Online spaces...

“Passive Combatants”: Online Discourses of the “Tamil Woman” and the 2009 Gardiner Expressway Occupation

“Passive Combatants”: Online Discourses of the “Tamil Woman” and the 2009 Gardiner Expressway Occupation

Analysis and Validation of Surrogate Safety Measures by Types of Lead and Following Vehicles

This study analyzed rear-end collision risk in a mixed traffic flow of cars and heavy vehicles on a freeway using two surrogate safety measures: time to collision (TTC) and postencroachment time (PET). The study estimated surrogate safety measures for types of lead and following vehicles (car or heavy vehicle) by using the individual vehicle trajectory data. The vehicle trajectory data were collected from a segment of the US-101 freeway in Los Angeles, California. It was found that the distributions of TTC and PET were significantly different between types of lead and following vehicles. Also, the mean values of TTC and PET were higher for heavy vehicles following cars than for cars following cars and for cars following heavy vehicles. The study also validated TTC by using the simulated traffic data for a few minutes before the time of crashes that occurred on a section of the Gardiner Expressway in Toronto, Ontario, Canada. It was found that TTC reflects higher collision risk in the time intervals closer to the crash time and it reflects higher collision risk for the crash case than for the noncrash case. The findings suggest that the difference in rear-end collision risk between types of vehicle pairs should be considered in safety assessment of mixed traffic flow of cars and heavy vehicles.

Investigation of the early-onset breakdown phenomenon at urban expressway bottlenecks in Shanghai

Based on the analyses of recurring bottlenecks in Shanghai's expressways using spatial–temporal diagrams, the method of transformed cumulative curves was used to investigate the traffic flow characteristics revealed by loop detector data at two typical isolated bottlenecks (a lane-drop and an on-ramp). The pre-queue flow (PQF) and queue discharge flow (QDF) of the two bottlenecks were analysed. The QDFs were an average of 18% and 27% higher than the PQF in the lane-drop and on-ramp bottlenecks, respectively. These findings differ from the results of bottlenecks in other countries (e.g. the M4 motorway near London, UK; I-494 in Minneapolis, MN, USA; the Queen Elizabeth Way (QEW) and the Gardiner Expressway in metropolitan Toronto, Canada) and indicate that lane-drop and on-ramp bottlenecks in Shanghai experience early onsets of traffic breakdown. The potential causes of the early onset of breakdown were discussed from the perspectives of driving behaviour, the temporal features of the flow rate and the features of merging.

Effect of Static Electronic Advertising Signs on Road Safety

As technology continues to advance, the outdoor advertising industry is taking advantage of electronic signs, some of which are static electronic signs (SES), with the ability to automatically change the message shown on the sign at regular intervals. Studies indicate that SES has a negative impact on the drivers' visual attention and on vehicle control. However, the actual effects of the SES on the number of collisions have been difficult to prove conclusively. The objective of this article is to generate a clear understanding of the safety impacts of SES on the number collisions by conducting a before-and-after analysis with comparison groups. The analysis was based on a total of 10 SES along the Highway 27 and the Gardiner Expressway of the city of Toronto. The results of the before-and-after study revealed that there was not enough evidence to suggest that these signs have any impact on road safety along the adjacent roadway sections at a 95% confidence interval. The same results were obtained by comparing collisions that occurred during daylight and artificial light.

ANOTHER PERSPECTIVE ON SUCCESS AND FAILURE CASE STUDIES IN CIVIL ENGINEERING DESIGN - THE GARDINER EXPRESSWAY

Civil engineering education at graduate and undergraduate levels commonly draws on structural engineering case studies, such as the 1907 Quebec Bridge Collapse or the 1981 Hyatt Regency Collapse to illustrate the significance of technical engineering design decisions, and their implications. A study of the Gardiner Expressway in a senior level civil engineering design course is valuable for a variety of reasons and are discussed in the paper. Construction of the Fredrick G. Gardiner Expressway, which acts as a main commuter route through Downtown Toronto, began in 1956 and was completed in 1965. Today, at over 50 years old, the expressway is experiencing traffic congestion, and visible degradation of structural materials, and consequently public safety may be compromised. This paper explores the history of the Gardiner Expressway and aspects of its design as it pertains to the current state of the aging infrastructure. There is a need for students to gain an understanding, exercise design skills and the design process in application to current, real world engineering design challenges such as aging structures and infrastructure.

Effects of Shock Waves on Freeway Crash Likelihood

This study examines how the formation and dissipation of a queue indicated by shock waves affect the likelihood of crash occurrence on freeways. Using one-minute average volume and density data collected from a section of the Gardiner Expressway in Toronto, changes in volume and density 3-10 minutes prior to the time of crash occurrence were observed. Types of shock wave and the shock wave speeds were estimated and related to the frequencies of the crashes where the shock wave existed before they occurred. It was found that typical shock wave types vary in different time periods of day due to different traffic conditions. The comparison with the volume-density data for the non-crash cases using logistic regression models shows that crashes are more likely to occur when the forward shock wave speed is lower. This indicates that slower vehicle progression in near-capacity conditions and slower dissipation of a queue in congested conditions are more likely to cause crashes. The results provide insights into better understanding of how shock waves affect the crash likelihood.

Safety Evaluation of Truck Lane Restriction Strategies Using Microsimulation Modeling

The demand for goods and services in North America has increased dramatically over the past few decades. This demand increase resulted in an associated increase in truck traffic on North American highways, escalating congestion, operation, and safety concerns. This in turn has led to increasing interest in strategies to reduce interaction between trucks and cars, including truck restrictions and dedicated truck lanes. The purpose of this paper is to implement algorithms for evaluating safety measures for different scenarios of truck lane restrictions and dedicated truck lanes using microscopic traffic simulation. The measures of performance calculated in this study are lane changing, merging, and rear-end conflicts. These measures are analyzed for truck-restricted lanes and dedicated truck lanes on the Gardiner Expressway in downtown Toronto, Canada. Simulation scenarios are developed by varying lane strategies and truck percentage. Simulation results showed that implementation of a single truck-restricted lane makes little difference to most conflict measures. Restricting trucks from the leftmost two lanes results in more substantial reductions in lane changing conflicts, but causes some increased freeway merging conflicts involving trucks. Dedicating the leftmost lane only to trucks also reduces lane changing conflicts but increases lane merging conflicts. Because lane changing conflicts are far more frequent than merging conflicts, there appears to be a net safety benefit by either restricting trucks from the left two lanes or dedicating the left lane to trucks. Relationships between lane strategy and rear-end conflicts are weak. Truck lane strategies are most effective when truck percentage exceeds 15%.

Road Capacity and Performance Implications of Ramp Closure Toronto, Canada, Experience

To alleviate traffic congestion and safety concerns on the Gardiner Expressway in Toronto, Ontario, Canada, the City of Toronto has elected to implement scheduled closures for the two on-ramps since early 1970s. This study investigates the traffic impacts of the daily on-ramp closures at Gardiner Expressway and Jameson Avenue. The average changes to traffic flow variables such as traffic volume throughput due to the ramp closures are computed quantitatively. Results show that ramp closure has resulted in smoother traffic flow and higher travel speed but not higher traffic throughput on the expressway. Ramp reopening causes a spike in speed variations as measured by upstream detectors. The network performance metrics (vehicle hours traveled, vehicle kilometers traveled, delay, and travel time) are computed and analyzed to determine the performance benefits of the ramp closures. The travel time saving in the area due to the ramp closure is estimated to be 225 vehicle-hours per day.

Monolith Makeover: The Art of Subversive Urban Enhancement

Recently, I was in a tall building in downtown Toronto with a panoramic south-facing window. I stopped for a minute to gaze at the endless stream of automobiles flowing along the Gardiner Expressway. As I spied on the concrete arteries bringing travellers to and through the city’s heart, my own heart bubbled over with memories of our summer fling. Suddenly, I felt like the heroine of a Hollywood movie contemplating a past lover from a distance with tenderness and passion. I was haunted by romantic recollections of the fleeting artistic relationship I had enjoyed with this highway. In the universe of site-specific installation and performance, the physical evidence of work may fade or vanish after minutes or months, but the memories, as they say, linger on.

Municipally managed gentrification in South Parkdale, Toronto

Earlier studies of Canadian inner‐city gentrification, especially in Toronto, project an image of the process as being emancipatory: a middle‐class reaction to the oppressive conformity of suburbia, modernist planning and market principles. This paper, a case study of gentrification in South Parkdale, Toronto, questions this image by illustrating the role of local context in theory and policy and the consequences of gentrification for vulnerable inner‐city populations. Once a desirable residential neighbourhood, South Parkdale experienced disinvestment following the construction of the Gardiner Expressway in the 1960s and also experienced further problems in the 1970s and 1980s following the deinstitution‐alisation of psychiatric patients from adjacent hospitals. Discharged patients suffered from a shortage of affordable housing options, and many ended up in substandard rooming houses and bachelorettes, of which South Parkdale has a disproportionate share in Toronto. The neighbourhood's sporadic gentrification since the mid‐1980s has intensified in recent years, as the City of Toronto is regularising and licensing the neighbourhood's low‐income housing—a major concern for tenants who fear that landlords will use recent provincial legislation on tenancy to attract wealthier residents into their improved buildings. This paper examines this situation with qualitative evidence and argues that gentrification in South Parkdale, driven and managed by neoliberal policy, is far from an emancipatory process and argues for an interpretation of gentrification that looks beyond the experiences of the middle classes.

Attracting The Eyes and Capitalizing on The Wallets: The Problem with Toronto’s New Public Performance Space

With the official opening of Yonge-Dundas Square last spring, the Toronto theatre and music communities gained a new outdoor performance venue, and the discount ticket seller TO TIX, a permanent home. The space itself is a curious addition to Toronto’s inner-city landscape. It’s a great, big, blank canvas of granite slabs, with a few concrete benches, a skinny canopy structure that is reminiscent of the Gardiner Expressway, and a double row of fountains that light up as the sky darkens. Surrounded as it is by concrete buildings and the honks and exhaust from a steady stream of cars, one might have hoped for a little green space. But one cannot argue that the square seems out of place; the design is urban grey and it blends visually into the urban grey that surrounds it. The granite slabs that line its surface are graphically reminiscent of the outdoor plazas of nearby skyscrapers, and the vertical lines of the pillars rhyme with the varying heights of the surrounding buildings. The square is formally compatible with its surroundings; the question is how well it will function under the hybrid identity assigned to it by the city. The city is marketing Yonge-Dundas Square as a public space, while at the same time encouraging it as a venue for private rental. Introducing twenty-four-hour surveillance, rental fees, and a plethora of advertising billboards charges the space with a political dimension and puts in doubt the idea that this is simply a new gathering space for public entertainments. Yonge-Dundas Square may at first appear as a genuine addition to Toronto’s public space, an exciting new performance venue to be shaped by citizen use, but it is also a commercial venture that aims to free itself from the city’s purse strings in three years’ time. Our role as active spectators obliges us to be conscious of the multiple, and sometimes conflicting, performative elements at play in this new venue.

Proactive freeway crash prevention using real-time traffic control

This paper makes use of a probabilistic model that predicts the likelihood of crashes (crash potential) on freeways on the basis of traffic flow conditions, in real-time crash prevention. The model was developed using incident logs and loop detector data collected over a 13-month period on the Gardiner Expressway in Toronto. Previous work suggested that an increase in levels of traffic turbulence generally yields high crash potential. Traffic turbulence was defined in terms of a series of crash precursors that represent traffic conditions that were present prior to crash occurrence. To apply the model in crash prevention, the link needs to be established between crash potential and real-time safety intervention. The objective of this paper is to explore this link for different thresholds of crash potential. The paper discusses the guidelines for evaluating the safety benefit of one crash prevention strategy (variable speed limits) and suggests the risk-based evaluation framework for real-time traffic control.Key words: crash, accident, freeway, safety, traffic flow, real-time control.

Analysis of Crash Precursors on Instrumented Freeways

Traffic flow characteristics that lead to crashes on urban freeways are examined. Since these characteristics are observed prior to crash occurrence, they are referred to as “crash precursors.” The objectives are ( a) to explore factors contributing to changes in crash rate for individual vehicles traveling over an urban freeway and ( b) to develop a probabilistic model relating significant crash precursors to changes in crash potential. The data used to examine crash precursors were extracted from 38 loop detector stations on a 10-km stretch of the Gardiner Expressway in Toronto for a 13-month period. An aggregate log-linear model was developed relating crash rates to the selected crash precursors observed upstream of the crash site. The results of this analysis suggest that the variation of speed and traffic density are statistically significant predictors of crash frequency after controlling for road geometry, weather, and time of day. With the model, crash potential can be established based on the precursors obtained from real-time traffic data.

New Insights into Freeway Capacity at Work Zones: Empirical Case Study

A construction project in Ontario, Canada, provided the opportunity to use field data to investigate freeway capacity at long-term lane closures due to rehabilitation work. Data from two lane closures at the same construction site (eastbound and westbound) were examined. The site is located on the Gardiner Expressway in the southern part of downtown Toronto. Data were collected during 4 days, totaling around 53 h of congested traffic operations. Results showed significant variation in freeway capacity in the work zones. Despite this variation, average capacity values are reasonably close to the corresponding values provided in the Highway Capacity Manual. Four intervening variables were investigated; all exhibited significant but different effects on freeway work-zone capacity. These variables included temporal variation (which is thought to relate to driver characteristics), grade, day of week, and weather conditions. The results confirmed the pressing need for more extensive field data that will allow better identification of the effect of various control variables on work-zone capacity.

Investigation of Speed-Flow Relationship Under Congested Conditions on a Freeway

The purpose of this work is to investigate the relationship between speed and flow within congestion, that is, the lower portion of the standard curve, and in particular to identify an equation to describe this portion of the relationship. Data were obtained for Toronto, Ontario, from the Gardiner Expressway RESCU System and the Highway 401 COMPASS System. The data were first screened to remove dubious data points and observations that were from transitions between congested and uncongested conditions. They were then analyzed using regression analysis for four types of function: quadratic, cubic, exponential, and power. The principal findings related to the shape of the speed-flow curve within congestion are as follows. It is important to utilize data from a full range of flows in order to fit a curve to represent the congested part of the speed-flow curve. To obtain this range, data from several sites may be needed. Despite the combination of sites, there is often what might be termed a “data gap” between easily available congested data (up to perhaps 1,800 vphpl) and flow rates for queue discharge flow. When data for that gap are available, the speeds under congested conditions seem to increase fairly rapidly at high congested flows. There appears to be a difference in the speed-flow relationship among different freeways and under construction conditions on one of them. If there are different curves for different freeways (or free-flow speeds) for the top half of the speedflow relationship, it seems reasonable that there might also be for the bottom half. However, it also appears to be the case that downstream conditions such as construction can affect the speed-flow curve itself at an upstream location. This makes sense in that operations within the queue are governed by the downstream queue discharge, but it is a change from what one expects for the other two segments of the speedflow curve.

Rehabilitation of prestressed concrete box beam deck of an elevated expressway

The object of this paper is to share the experience gained from a 4-year rehabilitation program on a section of the F. G. Gardiner Expressway in Toronto. The paper describes the latex-modified shotcrete repairs at locations of rusting strands at beam soffits and the conversion of original simply supported spans into continuous beams with the resulting elimination of nearly three fourths of the expansion joints. The benefits of continuity, reduction of expansion joints, new reinforced deck slab, and new drainage system are discussed and essential cost figures are provided. Key words: concrete, prestressed, bridge, rehabilitation, expressway, transportation, urban, shotcrete, continuity, expansion joint, composite deck, epoxied dowels, drainage.