Side impact accidents are considered to be the most dangerous of all types of intersection accide... more Side impact accidents are considered to be the most dangerous of all types of intersection accidents due to their high severity. In-depth investigation of accident occurrence could be a valuable means of mitigating these accidents. Based on the relationship between the distribution of disturbances near intersections and driers reactions, this study developed a logic for three major types of signalized intersections side impact crashes were considered for this study - right-angle, and left and right-turning crashes. The study developed models to understand the relationship between accident frequency and some explanatory variables that represent, driver, vehicle, traffic flow and intersection design characteristics. Negative binomial regression with maximum likelihood estimation of parameters is applied to address the overdispersion usually found in accident count data. The models explain the mechanism of side-impact accident occurrence and could be used to assist safety management ag...
<jats:p>Side impact accidents are considered to be the most dangerous of all types of inter... more <jats:p>Side impact accidents are considered to be the most dangerous of all types of intersection accidents due to their high severity. In-depth investigation of accident occurrence could be a valuable means of mitigating these accidents. Based on the relationship between the distribution of disturbances near intersections and driers reactions, this study developed a logic for three major types of signalized intersections side impact crashes were considered for this study - right-angle, and left and right-turning crashes. The study developed models to understand the relationship between accident frequency and some explanatory variables that represent, driver, vehicle, traffic flow and intersection design characteristics. Negative binomial regression with maximum likelihood estimation of parameters is applied to address the overdispersion usually found in accident count data. The models explain the mechanism of side-impact accident occurrence and could be used to assist safety management agencies to devise countermeasures aimed at divers, and the physical roadway environment.</jats:p>
Urban planning, infrastructure design, and mobility policy are up against a tough system-level ch... more Urban planning, infrastructure design, and mobility policy are up against a tough system-level challenge: the rapid adaptation of shared mobility. The new mobility is destabilizing the current auto-oriented transportation paradigm, and gradually moving toward a new mobility ecosystem. In order to capture the potential and create shared infrastructure, an innovative mobility planning model based on a scientific approach was developed to identify context-sensitive area solutions and the scaling of the proposed ecosystem for short- and long-term horizons. The aim of this model is to build capacities and competencies, enable municipal authority and system planners to quantify the scale and cost, and accurately model the potential impact and benefits of various innovative mobility strategies.
Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture... more Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture as the safer range of travel lane width. Traditional traffic engineers argue wider lanes are safer. Supporters of the livable street concept passionately promote the safety benefits of a relatively narrower lane width. Recent claims are emerging in favour of the livable street approach. However, neither side has yet produced any empirical evidence that links crash frequency or severity to lane width. This paper attempts to address this disquieting quandary. Extensive literature review, both academic and project reports or articles, has been conducted to examine recent claims and outline an emerging scientific perspective, and to provide an important logical platform for this research. In order to examine a relationship between lane width and crash rates, this study utilized two existing crash databases from Tokyo and Toronto, originally collected as part of greater effort to investigate...
Rapid adaptation of shared mobility is changing the current auto-oriented transportation paradigm... more Rapid adaptation of shared mobility is changing the current auto-oriented transportation paradigm towards new mobility ecosystem. Shift in lifestyle, engaging planning culture, demographic changes and rise of “pay-as-you-go” habits are paving the way of urban multimodal planning. Despite City’s new Official Plan policies acknowledging shared mobility and smart technologies, innovative mobility planning in public sector is struggling to adapt new shared economy. In order to capture the future potential and secure shared infrastructures, an innovative mobility master plan was developed to modify the current paradigm of city planning process. The intent of the master plan is to provide options for the residents and encourage creative ways to mitigate the negative impacts of vehicle uses. The study developed several scientific models for the short-and long-term horizons including active transportation and transit access facilities/connections, shared parking and supply management, variation of bicycle parking supply, vehicle sharing schemes (car-share, bike-share, carpool model), shared transit options at transit stations, real-time information systems, policy incentives, land use and smart growth concepts, and other work trip related programs. Based on the dynamic performance matrix, the study identifies expected measured outcome to maximize effectiveness and benefits. A unique partnership was developed with reward-based technology to collect data, monitor plan while taking advantage of real time system to reinforce the hard infrastructure network, connect multi modes and solve waiting problems. The aim of this model is to build capacities and competencies as well as enable municipal authority to quantify and accurately model the potential impact and benefits of various innovative mobility strategies. The model was applied to multiple planning areas in Toronto. The findings of the plan is expected to significantly alter the strategy of land development and inform municipal officials while correctly identifying the quantity and cost of new mobility programs.
Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture... more Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture as the safer range of travel lane width. Traditional traffic engineers argue wider lanes are safer. Supporters of the livable street concept passionately promote the safety benefits of a relatively narrower lane width. Recent claims are emerging in favour of the livable street approach. However, neither side has yet produced any empirical evidence that links crash frequency or severity to lane width. This paper attempts to address this disquieting quandary. Extensive literature review, both academic and project reports or articles, has been conducted to examine recent claims and outline an emerging scientific perspective, and to provide an important logical platform for this research. In order to examine a relationship between lane width and crash rates, this study utilized two existing crash databases from Tokyo and Toronto, originally collected as part of greater effort to investigate the occurrence mechanism for vehicle-to-vehicle side-impact crashes at signalized intersections. Five novel but identical evidences are discovered for both cities. Both narrow (less than 2.8m) and wide (over 3.1~3.2m) lanes have proven to increase crash risks with equal magnitude. Safety benefits bottom out around 3.1m (for Tokyo) and 3.2m (for Toronto). Beyond the “safety valley curve”, wider lanes (wider than 3.3m) adversely affect overall side-impact collisions. Secondly, among the types of crashes, right-turn crashes are relatively sensitive to lane width, while the safer range of lane width is relatively narrower for right-angle and left-turn crashes. Thirdly, the lateral displacement of driving maneuvers or oscillations stays within a narrow range (0.2m from bottom of safety curve), implying that humans display a surprisingly narrow “safety comfort zone” while trying to achieve a dynamic equilibrium status within the travel lane width. Fourthly, the capacity of narrower lanes is higher. No difference on safety and large vehicle carrying capacity is observed between narrower and wider lanes. Pedestrian volume declines as lanes widen, and intersections with narrower lanes provide the highest capacity for bicycles. Finally, wider lanes (over 3.3~3.4m), the predominant practice of Toronto regions, are associated with 33% higher impact speed rates and higher crash rates, despite higher traffic volumes and one-sixth the population than that of Tokyo. Given that the empirical evidence favours ‘narrower is safer’, the ‘wider is safer’ approach based on personal or intuitional opinion should be discarded once and for all. The findings acknowledge human behavior is impacted by the street environment, and narrower lanes in urban areas result in less aggressive driving and more ability to slow or stop a vehicle over a short distance to avoid collision. Designers of streets can utilize the “unused space” to provide an enhanced public realm, including cycling facilities and wider sidewalks, or to save money on the asphalt not used by motorists.
Drive-alone commuting is a predominant mode of existing transportation system during the peak per... more Drive-alone commuting is a predominant mode of existing transportation system during the peak periods and a major cause of traffic congestion. To combat this serious problem, Transportation Demand Management (TDM) offers truly sustainable solutions to optimize ‘system use.’ Although there are numerous TDM plans developed in Canada, the practitioners by and large develop TDM programs based on qualitative assessment (such as SWOT analysis) and personal intuition. However, intuition and opinion based planning is fallible guides to critical measures of reducing vehicle trip reduction strategy. “Soft” infrastructures, such as TDM programs, are relatively complex due to its interaction with human behaviour. Scientific approach of various TDM measures and quantitative assessment tools are being developed recently by shared mobility organizations. Estimating the TDM potential for all trips, however, is challenging. In order to capture potential candidate trips that could be diverted to TDM programs, an overall TDM master plan model was developed for urban areas. The intent of the TDM master plan, a new comprehensive approach to system management, is to provide options for the residents and to encourage the use of creative ways to mitigate the negative impacts vehicle uses. The type of TDM instruments are categorized into five types of instruments (planning/policy, physical, operational, financial/pricing, and institutional) with appropriate performance measurement indicators for future monitoring and evaluation. The study developed a total of eleven programs for the short-term and for long-terns horizons including active transportation and transit access facilities/connections, parking rate adjustment and supply management (including short and long-term bicycle parking), vehicle sharing schemes (car-share, bike-share, carpool model), travel information systems, financial incentives or pricing, land use and smart growth programs, and other work trip related programs.
Side impact accidents are considered to be the most dangerous of all types of intersection accide... more Side impact accidents are considered to be the most dangerous of all types of intersection accidents due to their high severity. In-depth investigation of accident occurrence could be a valuable means of mitigating these accidents. Based on the relationship between the distribution of disturbances near intersections and driers reactions, this study developed a logic for three major types of signalized intersections side impact crashes were considered for this study - right-angle, and left and right-turning crashes. The study developed models to understand the relationship between accident frequency and some explanatory variables that represent, driver, vehicle, traffic flow and intersection design characteristics. Negative binomial regression with maximum likelihood estimation of parameters is applied to address the overdispersion usually found in accident count data. The models explain the mechanism of side-impact accident occurrence and could be used to assist safety management ag...
<jats:p>Side impact accidents are considered to be the most dangerous of all types of inter... more <jats:p>Side impact accidents are considered to be the most dangerous of all types of intersection accidents due to their high severity. In-depth investigation of accident occurrence could be a valuable means of mitigating these accidents. Based on the relationship between the distribution of disturbances near intersections and driers reactions, this study developed a logic for three major types of signalized intersections side impact crashes were considered for this study - right-angle, and left and right-turning crashes. The study developed models to understand the relationship between accident frequency and some explanatory variables that represent, driver, vehicle, traffic flow and intersection design characteristics. Negative binomial regression with maximum likelihood estimation of parameters is applied to address the overdispersion usually found in accident count data. The models explain the mechanism of side-impact accident occurrence and could be used to assist safety management agencies to devise countermeasures aimed at divers, and the physical roadway environment.</jats:p>
Urban planning, infrastructure design, and mobility policy are up against a tough system-level ch... more Urban planning, infrastructure design, and mobility policy are up against a tough system-level challenge: the rapid adaptation of shared mobility. The new mobility is destabilizing the current auto-oriented transportation paradigm, and gradually moving toward a new mobility ecosystem. In order to capture the potential and create shared infrastructure, an innovative mobility planning model based on a scientific approach was developed to identify context-sensitive area solutions and the scaling of the proposed ecosystem for short- and long-term horizons. The aim of this model is to build capacities and competencies, enable municipal authority and system planners to quantify the scale and cost, and accurately model the potential impact and benefits of various innovative mobility strategies.
Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture... more Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture as the safer range of travel lane width. Traditional traffic engineers argue wider lanes are safer. Supporters of the livable street concept passionately promote the safety benefits of a relatively narrower lane width. Recent claims are emerging in favour of the livable street approach. However, neither side has yet produced any empirical evidence that links crash frequency or severity to lane width. This paper attempts to address this disquieting quandary. Extensive literature review, both academic and project reports or articles, has been conducted to examine recent claims and outline an emerging scientific perspective, and to provide an important logical platform for this research. In order to examine a relationship between lane width and crash rates, this study utilized two existing crash databases from Tokyo and Toronto, originally collected as part of greater effort to investigate...
Rapid adaptation of shared mobility is changing the current auto-oriented transportation paradigm... more Rapid adaptation of shared mobility is changing the current auto-oriented transportation paradigm towards new mobility ecosystem. Shift in lifestyle, engaging planning culture, demographic changes and rise of “pay-as-you-go” habits are paving the way of urban multimodal planning. Despite City’s new Official Plan policies acknowledging shared mobility and smart technologies, innovative mobility planning in public sector is struggling to adapt new shared economy. In order to capture the future potential and secure shared infrastructures, an innovative mobility master plan was developed to modify the current paradigm of city planning process. The intent of the master plan is to provide options for the residents and encourage creative ways to mitigate the negative impacts of vehicle uses. The study developed several scientific models for the short-and long-term horizons including active transportation and transit access facilities/connections, shared parking and supply management, variation of bicycle parking supply, vehicle sharing schemes (car-share, bike-share, carpool model), shared transit options at transit stations, real-time information systems, policy incentives, land use and smart growth concepts, and other work trip related programs. Based on the dynamic performance matrix, the study identifies expected measured outcome to maximize effectiveness and benefits. A unique partnership was developed with reward-based technology to collect data, monitor plan while taking advantage of real time system to reinforce the hard infrastructure network, connect multi modes and solve waiting problems. The aim of this model is to build capacities and competencies as well as enable municipal authority to quantify and accurately model the potential impact and benefits of various innovative mobility strategies. The model was applied to multiple planning areas in Toronto. The findings of the plan is expected to significantly alter the strategy of land development and inform municipal officials while correctly identifying the quantity and cost of new mobility programs.
Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture... more Of all street design elements, no other has evoked as much bafflement, incredulity and conjecture as the safer range of travel lane width. Traditional traffic engineers argue wider lanes are safer. Supporters of the livable street concept passionately promote the safety benefits of a relatively narrower lane width. Recent claims are emerging in favour of the livable street approach. However, neither side has yet produced any empirical evidence that links crash frequency or severity to lane width. This paper attempts to address this disquieting quandary. Extensive literature review, both academic and project reports or articles, has been conducted to examine recent claims and outline an emerging scientific perspective, and to provide an important logical platform for this research. In order to examine a relationship between lane width and crash rates, this study utilized two existing crash databases from Tokyo and Toronto, originally collected as part of greater effort to investigate the occurrence mechanism for vehicle-to-vehicle side-impact crashes at signalized intersections. Five novel but identical evidences are discovered for both cities. Both narrow (less than 2.8m) and wide (over 3.1~3.2m) lanes have proven to increase crash risks with equal magnitude. Safety benefits bottom out around 3.1m (for Tokyo) and 3.2m (for Toronto). Beyond the “safety valley curve”, wider lanes (wider than 3.3m) adversely affect overall side-impact collisions. Secondly, among the types of crashes, right-turn crashes are relatively sensitive to lane width, while the safer range of lane width is relatively narrower for right-angle and left-turn crashes. Thirdly, the lateral displacement of driving maneuvers or oscillations stays within a narrow range (0.2m from bottom of safety curve), implying that humans display a surprisingly narrow “safety comfort zone” while trying to achieve a dynamic equilibrium status within the travel lane width. Fourthly, the capacity of narrower lanes is higher. No difference on safety and large vehicle carrying capacity is observed between narrower and wider lanes. Pedestrian volume declines as lanes widen, and intersections with narrower lanes provide the highest capacity for bicycles. Finally, wider lanes (over 3.3~3.4m), the predominant practice of Toronto regions, are associated with 33% higher impact speed rates and higher crash rates, despite higher traffic volumes and one-sixth the population than that of Tokyo. Given that the empirical evidence favours ‘narrower is safer’, the ‘wider is safer’ approach based on personal or intuitional opinion should be discarded once and for all. The findings acknowledge human behavior is impacted by the street environment, and narrower lanes in urban areas result in less aggressive driving and more ability to slow or stop a vehicle over a short distance to avoid collision. Designers of streets can utilize the “unused space” to provide an enhanced public realm, including cycling facilities and wider sidewalks, or to save money on the asphalt not used by motorists.
Drive-alone commuting is a predominant mode of existing transportation system during the peak per... more Drive-alone commuting is a predominant mode of existing transportation system during the peak periods and a major cause of traffic congestion. To combat this serious problem, Transportation Demand Management (TDM) offers truly sustainable solutions to optimize ‘system use.’ Although there are numerous TDM plans developed in Canada, the practitioners by and large develop TDM programs based on qualitative assessment (such as SWOT analysis) and personal intuition. However, intuition and opinion based planning is fallible guides to critical measures of reducing vehicle trip reduction strategy. “Soft” infrastructures, such as TDM programs, are relatively complex due to its interaction with human behaviour. Scientific approach of various TDM measures and quantitative assessment tools are being developed recently by shared mobility organizations. Estimating the TDM potential for all trips, however, is challenging. In order to capture potential candidate trips that could be diverted to TDM programs, an overall TDM master plan model was developed for urban areas. The intent of the TDM master plan, a new comprehensive approach to system management, is to provide options for the residents and to encourage the use of creative ways to mitigate the negative impacts vehicle uses. The type of TDM instruments are categorized into five types of instruments (planning/policy, physical, operational, financial/pricing, and institutional) with appropriate performance measurement indicators for future monitoring and evaluation. The study developed a total of eleven programs for the short-term and for long-terns horizons including active transportation and transit access facilities/connections, parking rate adjustment and supply management (including short and long-term bicycle parking), vehicle sharing schemes (car-share, bike-share, carpool model), travel information systems, financial incentives or pricing, land use and smart growth programs, and other work trip related programs.
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