Posts Tagged: Transportation

Toronto’s COVID-19 bike lane expansion boosted access to jobs, retail: U of T study

A study by U of T Engineering researchers found Toronto’s temporary cycling infrastructure increased low-stress road access to jobs and food stores by between 10 and 20 per cent, and access to parks by 6.3 per cent (photo by Dylan Passmore)

With COVID-19 making it vital for people to keep their distance from one another, the city of Toronto undertook the largest one-year expansion of its cycling network in 2020, adding about 25 kilometres of temporary bikeways.

Yet, the benefits of helping people get around on two wheels go far beyond facilitating physical distancing, according to a recent study by three University of Toronto researchers that was published in the journal Transport Findings.

Bo Lin, Shoshanna Saxe, and Timothy Chan.

PhD candidate Bo Lin (MIE) with Professors Shoshanna Saxe (CivMin), and Timothy Chan (MIE), all of the Faculty of Applied Science & Engineering, used census, city and survey data to map Toronto’s entire cycling network – including the new routes – and found that additional bike infrastructure increased low-stress road access to jobs and food stores by between 10 and 20 per cent, while boosting access to parks by an average of 6.3 per cent.

“What surprised me the most was how big an impact we found from what was just built last summer,” says Saxe, an assistant professor in the department of civil and mineral engineering.

“We found sometimes increases in access to 100,000 jobs or a 20 per cent increase. That’s massive.”

The impact of bikeways added during COVID-19 were greatest in areas of the city where the new lanes were grafted onto an existing cycling network near a large concentration of stores and jobs, such as the downtown core. Although there were new routes installed to the north and east of the city, “these areas remain early on the S-Curve of accessibility given the limited links with pre-existing cycling infrastructure,” the study says.

In these areas, the new infrastructure can be the beginning of a future network as each new lane multiplies the impact of ones already built, Saxe says.

As for the study’s findings about increasing access to jobs, Saxe says they are not only a measure of access to employment but also a proxy for places you would want to travel to: restaurants, movie theatres, music venues and so on.

A map of Toronto’s bikeway network with colours representing the route’s level of stress (image courtesy of Bo Lin)

The researchers used information from Open Data Toronto and the Transportation Tomorrow 2016 survey, among other sources. Where there were discrepancies, Lin, a PhD student and the study’s lead author, gathered the data himself by navigating the city’s streets (as a bonus, it helped him get to know Toronto after moving here from Waterloo, Ont.).

“There were some days I did nothing but go around the city using Google Maps,” he says.

For Lin, the research has opened up new avenues of investigation into cycling networks, including how bottlenecks can have a ripple effect through the system.

The study, like some of Saxe’s past work on cycling routes, makes a distinction between low- and high-stress bikeways to get a more accurate reading of how they affect access to opportunities. At the lowest end of the scale are roads where a child could cycle safely; on the other end are busy thoroughfares for “strong and fearless cyclists” – Avenue Road north of Bloor Street, for example.

“It’s legal to cycle on most roads, but too many roads feel very uncomfortable to bike on,” Saxe says.

For Saxe, the impact of the new cycling routes shows how a little bike infrastructure can go a long way.

“Think about how long it would have taken us to build 20 kilometres of a metro project – and we need to do these big, long projects – but we also have to do short-term, fast, effective things.”

Chan, a professor of industrial engineering in the department of mechanical and industrial engineering, says the tools they used to measure the impact of the new bikeways in Toronto will be useful in evaluating future expansions of the network, as well as those found in other cities.

“You hear lots of debates about bike lanes that are based on anecdotal evidence,” he says. “But here we have a quantitative framework that we can use to rigorously evaluate and compare different cycling infrastructure projects.

“What gets me excited is that, using these tools, we can generate insights that can influence decision-making.”

The U of T team’s research, which was supported by funding from the City of Toronto, may come in handy sooner rather than later. Toronto’s city council is slated to review the COVID-19 cycling infrastructure this year.

ByGeoffrey Vendeville

 

This story originally published by U of T News


The UrbanScanner Project: Mobile monitoring of air pollution in cities

Prof. Marianne Hatzopoulou (left) and her research team, comprised of MASc candidate Keni Mallinen (centre) and Arman Ganji , PhD (right), with the UrbanScanner on the Uof T campus. UrbanScanner is  a rolling laboratory capable of monitoring air quality, traffic, trees and built environment in urban settings. (Photo by Phill Snel)

 

What rolls around the city getting a lot of admiring looks for its flashy chromed finishes and high tech roof protrusions? It’s not the latest tech from a popular web search engine company; it’s something entirely different. Meet UrbanScanner, a mobile testing laboratory on wheels, in the form of an automobile, researchers are driving around Toronto to monitor air pollution.

The Transportation and Air Quality (TRAQ) research group within the Department of Civil & Mineral Engineering at U of T, led by Prof. Marianne Hatzopoulou, has partnered with Scentroid, a Toronto-based company developing sensor-based systems for urban air pollution monitoring. The result is the development of UrbanScanner.

Hatzopoulou’s team, comprised of research associate Arman Ganji, PhD and Keni Mallinen, an MASc candidate, has been getting a lot of looks while gathering their data, but little is known about this mysteriously well-equipped rolling lab.

Watch an introductory video:

With a 360-degree camera, LIDAR (Light Detection and Ranging), GPS, an ultrasonic anemometer, temperature and relative humidity sensors, as well as particulate matter and gas sensors, UrbanScanner can monitor air pollution in a variety of methods. A platform on the roof of the vehicle streams data to a cloud server, with air pollution measured every second and paired with the camera and LIDAR images.

An example of UrbanScanner data points collected for pollution concentration overlapped with a City of Toronto street map.

Besides air quality, the traffic, trees and built environment are constantly measured. All of the data is overlaid over city maps with the aid of GPS, allowing for real-time measurements of traffic flow, number and height of trees, as well as building forms. With the ability to measure air flow and pollution near built-up urban areas, the maps can reveal elevated pollution levels, especially at rush hour and depending upon the season.

All of the data collected thus far takes time and effort to process, but Hatzopoulou has plans going forward. “Since September 2020, UrbanScanner has been collecting air quality data across Toronto, both along major roads and within Toronto neighbourhoods,” she says. “These data were paired with images of the urban environment from the UrbanScanner camera and these images will be analyzed to extract important features that affect air quality. This massive database will continue to grow as UrbanScanner collects data across seasons and will help us predict air quality in space and time, providing crucial information about population exposures in the City.”

A graphical abstract for the UrbanScanner project shows urban routes, samples taken and mapping.

Hatzopoulou adds, “Our team is also working on a smaller, more compact version of UrbanScanner with multiple units that will be installed on commercial/delivery vehicles. Imagine a dozen UrbanScanners collecting data simultaneously every day in Toronto!”

The research team is also developing a website to share data from the UrbanScanner project with the public and working on ways to enhance public engagement around urban air quality.

So, now if you see UrbanScanner in your neighbourhood you’ll know exactly what the team is up to. Please feel free to take a snap and tag #UrbanScanner and @CivMin.

By Phill Snel

 

By the numbers:

~250,000 • Number of data points collected in a month.

2,280 • Kilometres driven in a month of study.

101  • Hours of collection data.

60 • Kilometres driven each day of monitoring.

14 • Sensors on UrbanScanner.

4 • Wheels.

3 • Researchers.

2 • Seats in UrbanScanner.

1 • Mobile laboratory platform.

~ CivMin ~

 

 

 

 


CivMin faculty and students garner CSCE recognition

CivMin professors and students honoured by CSCE: (top row L to R) Prof. Khander Habib, Prof. Doug Hooton, Prof. Jeffrey Packer with (bottom row L to R) graduate research students Jens Kuhn and YuJing Fan, and Prof. Frank Vecchio.

The Canadian Society for Civil Engineering (CSCE) announced its 2020 Honours, Awards and Fellowships, recognizing several CivMin faculty and students.

Among those recognized by the CSCE are Prof. Khander Habib, Prof.Doug Hooton, Prof. Jeffrey Packer, along with graduate students Jens Kuhn and YuJing Fan (CivE MASc 1T7), and Prof. Frank Vecchio.

Sandford Fleming Award
Prof. Khander Habib presented the Sandford Fleming Award for 2020. The award is presented annually to a member of the CSCE who has made particularly outstanding contributions to the development and practice of transportation engineering in Canada.

Habib has been a professor at the University of Toronto since 2010. Habib received his BSc. (2000) and MSc. (2002) degrees in Civil Engineering from Bangladesh University of Engineering & Technology. He received his Ph.D. (2007) from the University of Toronto. Before joining the University of Toronto, he served as a Professor in the Department of Civil & Environmental Engineering of the University of Alberta (2007-2010). Habib received several awards including Eric Pass Award (Honorable mention) from the International Association of Travel Behaviour Research; Early Researcher Award from Ontario Ministry of Economic Development and Innovation; Minister’s Award for (transportation) Process Innovation from Alberta Ministry ofTransportation; Pyke Johnson Award and numerous best paper awards as well as certificates of appreciation from theTransportation Research Board (TRB) of US National Academies of Science, Engineering and Medicine; Educational Achievement Award from the Transportation Association of Canada, Trottier Fellowship at the Institut de Energie Trottier in Montreal; Dean’s Merit Pool awards and Percy Edward Hart Professorship from the Faculty of Applied Science and Engineering at the University ofToronto. He serves editorial boards of several top-tire transportation journals and works as an editor of two journals. He is a member of TRB’s standing committees on transportation demand forecasting and travel behaviour analysis.

Areas of Expertise: Strategic transportation planning, travel demand modelling, travel survey methods, transport economics, transport policy, econometric choice modelling, emerging transportation technologies, and smart cities in the era of automated and transformative transportation (on-demand mobility, ride-sourcing and sharing economy).

 

Fellow of the Canadian Society for Civil Engineering
Prof. Doug Hooton is recognized as a Fellow of the Canadian Society for Civil Engineering 2020.

Robert Douglas Hooton is a Professor in the University ofToronto’s Department of Civil Engineering and holds the NSERC/ Cement Association of Canada Senior Industrial Research Chair in Concrete Durability and Sustainability. He received his BASc (1974) and MASc (1975) from University of Toronto and PhD (1981) from McMaster University. Dr. Hooton is a registered Professional Engineer in Ontario and in addition to being a member of the Canadian Society of Civil Engineers, he is a Fellow of the Engineering Institute of Canada and the Canadian Academy of Engineering. He is an Honorary member of the American Concrete Institute (ACI), and Honorary Fellow of the Institute of Concrete Technology (UK), Fellow of RILEM, Fellow of the American Ceramic Society, and Fellow of ASTM.

He received the Engineering Institute of Canada’s Julian C. Smith Medal (2016), the Ontario Professional Engineers Medal for Research and Development (2012), ACI’s Wason Research Medal (2014), as well as ACI’s R.E. Philleo (2013), and A.R. Anderson (2011) awards, and the CSA Award of Merit (1997). Well known as an expert on both Cementitious Materials and Concrete Durability, he has been active on over 40 standards, technical, and code committees in North America and Europe, holding a number of leadership positions on these committees. Several new standard test methods and building code changes related to concrete durability in Canada and the U.S.A. have been developed or championed by him based on the results of his research.

 

Casimir Gzowski Medal
Prof. Jeffrey Packer, with students Jens Kuhn and YuJing Fan, are awarded The Casimir Gzowski Medal for 2020 for their paper on Rectangular hollow section webs under transverse compression (cjce-2018-0485). Established by Sir Casimir in 1890, the Casimir Gzowski Medal is awarded annually for the best civil engineering paper in surveying, structural engineering or heavy construction.

Abstract: An investigation is presented into full-width, RHS X-connections subject to transverse compression, including the effect of a compressive or tensile chord preload. A re-evaluation of world-wide experimental tests on fullwidth X-connections revealed considerable inaccuracy with current design recommendations, as well as significant discrepancies between them. A finite element study was hence conducted to further investigate the behaviour of such connections. A critical value of the bearing length-to-chord height ratio was found, where yielding failure of the chord webs turns into buckling failure, and this has been implemented in the subsequent design recommendation. e proposed design procedure is based on 350 finite element results, covering a wide range of chord sidewall slenderness values, bearing length values and chord stress ratios, as well as against a screened data base of 125 experimental tests. The proposal is shown to offer excellent predictions and incorporates a simple reliability analysis.

 

A.B. Sanderson Award
Prof. Frank Vecchio, is presented the A.B. Sanderson Award for 2020. The award is presented to a member of the CSCE who has made particularly outstanding contributions to the development and practice of structural engineering in Canada.

Frank J. Vecchio, Ph.D., P.Eng., is Professor and Bahen/Tanenbaum Chair in Civil Engineering in the Department of Civil & Mineral Engineering at the University ofToronto. He has been on Faculty since 1985. Dr. Vecchio received his doctorate from the University of Toronto (1981), where he also received his B.A.Sc. (1978) and M.Eng. (1979) degrees. Prior to joining the Faculty at the University ofToronto, he was employed as a research engineer at Ontario Hydro (1981-1985). He is a registered Professional Engineer in Ontario. His research interests relate to the development of improved analysis procedures for reinforced concrete structures, particularly for those that are shear-sensitive. Recent activities include the development of improved constitutive models and nonlinear finite element procedures, application to the assessment and forensic analysis of concrete structures, and analysis of damaged, repaired or rehabilitated structures. Additional interests include the modelling and assessment of fibre reinforced concrete (FRC) structures, structures rehabilitated with fibre reinforced polymers (FRP), and structures subjected to extreme loads including blast, impact, fire and earthquake. He is the author of over 120 technical papers in these areas.

Dr. Vecchio is a Fellow of the Canadian Society of Civil Engineers (CSCE) and former recipient of the CSCE Whitman-Wright Award (2011) and Horst Leipholz Medal (2014), and the Ontario Professional Engineers Engineering Medal – Research and Development (2014). He continues to be an active member of several international technical societies and committees relating to the design and assessment of reinforced concrete structures.

 

From the CSCE’s 2020 Honours, Awards and Fellowships


Four U of T transportation students win WTS Toronto area chapter scholarships

Four U of T transportation students, three from CivMin, have been awarded “Advancing Women in Transportation” scholarships by the WTS Toronto area chapter. From top left, clockwise: Felita Ong (CivE MASc candidate), Mahia Anhara (CivE third year), Alaa Itani (CivE PhD candidate), and Joanna Ilunga-Kapinga (MScPl candidate).

 

 

University of Toronto students Mahia Anhara (Year 3 CivE), Joanna Ilunga-Kapinga (MScPl candidate), Alaa Itani (CivE PhD candidate), and Felita Ong (CivE MASc candidate) have been awarded “Advancing Women in Transportation” scholarships by the WTS Toronto area chapter.

The scholarships were announced at the WTS Virtual Conference on Wednesday, December 3, 2020.

head shot of Mahia Anhara

Mahia Anhara

Mahia Anhara is an undergraduate Civil Engineering student at the University of Toronto with a keen interest in transportation engineering. After completing her third year, she began working as an Engineering Intern in the Vision Zero Projects Unit at the City of Toronto, as a part of her Professional Experience Year. Currently in this role, Mahia is helping to eliminate traffic-related fatalities and serious injuries by designing safer streets and intersections for all road users. She was also involved in designing temporary bike lanes on a major road in her neighbourhood, which enables her to bike conveniently and safely to stores, the library, and parks.

At U of T Mahia is very involved in U of T Engineering clubs. She is currently the PEY Representative and a mentor in the Civil Engineering Discipline Club. She is also a Project Manager in the Canadian Electrical Contractors Association (CECA) – U of T Student Chapter.

Mahia believes that roads should not only be designed for motorists, but for all road users, such as pedestrians, cyclists, and transit users so that everyone can access amenities and opportunities safely and equitably.

She wants to pursue a career in developing transportation systems that provide people from all walks of life with improved transit access and safer streets for biking and walking. She looks forward to being an agent in transforming cities to become more resilient and vibrant.

In her own words:

“Many North American cities have been designed in a way to prioritize automobiles. This has led to the rise of inequality, degradation of physical and mental health, and the exacerbation of climate change. I’m inspired to study transportation to help address these issues and make cities more walkable, bikeable, and transit-friendly.”

Mahia believes, like WTS, that supporting female transportation professionals is important:

“It’s important to have more women in the transportation industry as they can bring alternative perspectives to the table and voice their own experiences of using the transportation system. This will lead to better-informed decisions that reflect the needs of diverse users.”


head shot of Joanna Ilunga-Kapinga

Joanna Ilunga-Kapinga

Joanna Ilunga-Kapinga is currently a graduate student in the Masters of Science in Planning program at the University of Toronto. Her CIP supervisor is Professor Matti Siemiatycki.

In 2019, Joanna completed her undergraduate degree at the University of Toronto with an Honours Bachelor of Arts degree with distinction, with a double major (Peace, Conflict, and Justice Studies, and Political Science).

Joanna’s research focuses on transit-oriented development, vertical housing, mixed-use buildings, and city accessibility for individuals with disabilities. Her specialties include policy development and analysis, project management, transportation and urban planning, research analysis, stakeholder engagement, community building, and strategic planning. Joanna is also very interested in the Belt and Road Initiative happening in the Global South. This interest influenced and pushed her to pursue a degree in planning. She believes that good transportation improves access to economic and social qualities of life for all.

Joanna currently serves as the 2020-2021 Urban Land Institute Representative for the second year cohort in the Department of Geography and Planning on the ULI Student Committee, and as a Compliance Director for the G7 Research Group at the University of Toronto.

When she’s not in class, Joanna enjoys creating curated playlists on Spotify, reading, watching foreign films, interior designing, and exploring the city for the most creative built forms and the best pastries.

Joanna says:

“I want to be part of the movement that includes women and people of colour with opportunity to be part of the projects and changes that shape neighbourhoods. I am extremely interested in transportation projects and making improvements to the current systems we have in place and I want to be part of identifying problems and devising more accessible transportation routes. I am very passionate about policy and I want to be involved and learn from the best on how to plan, learn and activate change.”


head shot of Alaa Itani outside on U of T grounds

Alaa Itani

Alaa is a second-year PhD student at the University of Toronto Department of Civil and Mineral Engineering specializing in public transit operations and research under the supervision of Professor Amer Shalaby. She is interested in the field of bus-hailing, dial-a-ride, and flexible transit services where her research focuses on planning and understanding the policies and guidelines of these services in this era of emerging technology and automation.

She obtained her Master’s degree from the University of Toronto in 2019 and a Bachelor’s degree in Civil and Environmental Engineering from the American University of Beirut in Lebanon in 2017.

An active volunteer, Alaa is currently Administrative Officer of the University of Toronto ITE Student Chapter. She also executed multiple volunteer roles at the recent TransitData 2020 online international symposium.

Since January 2020, Alaa has presented her research at four public forums, beginning with the prestigious Annual Meeting of the Transportation Research Board in January. In April, she presented at Esri Canada’s “GIS in Education and Research Conference.” In June, Alaa presented at both “Transformative Transportation ’20” and the “iCity Research Days Webinar Series.”

In addition to volunteering and presenting her research, Alaa also participated in a hackathon on urban transit data, and most recently, in the 2020 ITS Canada Essay Competition where she won second prize.

Alaa is motivated by her personal, lived experience. She explains:

“I have a passion for transit and I will continue working towards more equitable transportation options, as I grew up in a city that did not have a public transport network, and I struggled a lot getting around in my own city.”


head shot of Felita Ong

Felita Ong

Felita Ong is an MASc student at the University of Toronto Department of Civil and Mineral Engineering under the supervision of Professor Khandker Nurul Habib. She obtained a BASc in Civil Engineering from the University of British Columbia and has experience in transportation planning and operations through her work in both the public and private sectors.

Felita’s research focuses on investigating the demand competition between ride-hailing services and public transit to help transit agencies make evidence-based policies and planning decisions.

Felita is passionate about introducing young students to STEM, including transportation engineering. She is currently a high school mentor through the Women in Science and Engineering (WISE) U of T Chapter, and was previously an instructor for the UBC Geering Up Engineering Outreach, a non-profit organization that promotes STEM to young students throughout British Columbia.

Felita is proud that her research has real-world benefits. She says:

“Transportation is a multidisciplinary field that has a direct impact on everyday lives. I hope to contribute to a sustainable, equitable, and efficient transportation system.”


WTS Toronto area chapter scholarship announcement

About WTS

The scholarship donor organization, WTS (Women’s Transportation Seminar) International, was founded in 1977 by a group of pioneering women in transportation who realized that women’s careers would benefit from professional development, encouragement and recognition to support their advancement in transportation professions. It is a member organization with chapters worldwide, including the WTS Toronto Area Chapter established in 2013.

By Pat

This story originally posted by UTTRI


CivMin study: Electric vehicles can fight climate change, but they’re not a silver bullet

Sales of passenger electric vehicles are growing fast, but a new analysis from U of T Engineering researchers shows that on its own, electrifying the U.S. fleet will not be enough to meet our climate change mitigation targets. (Photo: microgen, via Envato)

Today there are more than 7 million electric vehicles (EVs) in operation around the world, compared with only about 20,000 a decade ago. It’s a massive change — but according to a group of U of T Engineering researchers, it won’t be nearly enough to address the global climate crisis. 

“A lot of people think that a large-scale shift to EVs will mostly solve our climate problems in the passenger vehicle sector” says Alexandre Milovanoff, lead author of a new paper published today in Nature Climate Change. 

“I think a better way to look at it is this: EVs are necessary, but on their own, they are not sufficient.” 

Around the world, many governments are already going all-in on EVs. In Norway, for example, where EVs already account for half of new vehicle sales, the government has said it plans to eliminate sales of new internal combustion vehicles altogether by 2025. The Netherlands aims to follow suit by 2030, with France and Canada to follow by 2040. Just last week, California announced plans to ban sales of new internal combustion vehicles by 2035.

Milovanoff and his supervisors, Professors Daniel Posen and Heather MacLean (both CivMin) are experts in life cycle assessment — modelling the impacts of technological changes across a range of environmental factors. 

They decided to run a detailed analysis of what a large-scale shift to EVs would mean in terms of emissions and related impacts. As a test market, they chose the United States, which is second only to China in terms of passenger vehicle sales. 

“We picked the U.S. because they have large, heavy vehicles, as well as high vehicle ownership per capita and high rate of travel per capita,” says Milovanoff. “There is also lots of high-quality data available, so we felt it would give us the clearest answers.” 

The team built computer models to estimate how many electric vehicles would be needed to keep the increase in global average temperatures to less than 2 C above pre-industrial levels by the year 2100, a target often cited by climate researchers. 

“We came up with a novel method to convert this target into a carbon budget for U.S. passenger vehicles, and then determined how many EVs would be needed to stay within that budget,” says Posen. “It turns out to be a lot.” 

Based on the scenarios modelled by the team, the U.S. would need to have about 350 million EVs on the road by 2050 in order to meet the target emissions reductions. That works out to about 90% of the total vehicles estimated to be in operation at that time. 

“To put that in perspective, right now the total proportion of EVs on the road in the U.S. is about 0.3%,” says Milovanoff. 

“It’s true that sales are growing fast, but even the most optimistic projections suggest that by 2050, the U.S. fleet will only be at about 50% EVs.” 

The team says that in addition to the barriers of consumer preferences for EV deployment, there are technological barriers such as the strain that these vehicles would place on the country’s electricity infrastructure. 

According to the paper, a fleet of 350 million EVs would increase annual electricity demand by 1,730 TWh, or about 41% of current levels. This would require massive investment in infrastructure and new power plants, some of which would almost certainly run on fossil fuels. 

The shift could also impact what’s known as the demand curve — the way that demand for electricity rises and falls at different times of day — which would make managing the national electrical grid more complex. Finally, there are technical challenges to do with the supply of critical materials, such as lithium, cobalt and manganese for batteries. 

The team concludes that getting to 90% EV ownership by 2050 is an unrealistic scenario. Instead, what they recommend is a mix of policies, including many designed to shift people out of personal passenger vehicles in favour of other modes of transportation. 

These could include massive investment in public transit — subways, commuter trains, buses — as well as the redesign of cities to allow for more trips to be taken via active modes, such as bicycles or on foot. They could also include strategies such as telecommuting, a shift already spotlighted by the COVID-19 pandemic. 

“EVs really do reduce emissions, but they don’t get us out of having to do the things we already know we need to do,” says MacLean. “We need to rethink our behaviours, the design of our cities, and even aspects of our culture. Everybody has to take responsibility for this.” 

By Tyler Irving

 

This story originally published in Engineering News


Is there a better way for transit systems to deal with service disruptions?

A crowd spills along Bloor street after a transit disruption in November 2009. U of T Engineering research have designed an algorithm that they say can more efficiently dispatch buses to deal with downed subway lines. (Photo: Sweetsop, via Flickr)

 

It’s a phrase transit riders hear all too often: “Shuttle buses are on the way.”

Service disruptions are a fact of life for transit systems around the world. The most common remedy is “bus bridging,” in which buses are pulled from regular routes and dispatched to serve as shuttles along the disrupted rail segment.

But the transition rarely goes smoothly. If the buses are not dispatched in time, or if there are not enough of them along a given route, the result is overcrowding, delays and less efficient operation. In New York City alone, major subway disruptions have been estimated to cost $389 million per year in lost wages and productivity.

Professor Amer Shalaby (CivMin) and his team are working on solutions. Over the past few years, they have conducted a number of studies to pinpoint the key factors that determine successful bus bridging deployment, and developed tools that transit agencies can use to make better decisions.

“Bus bridging has gained growing attention in recent years due to the dire need for more efficient strategies to counter the effects of unplanned disruptions of rail service, which are happening more frequently,” says Shalaby. “Our approach is unique in terms of the balance it achieves between a theoretically robust procedure and practical application.”

Much of the team’s work has been conducted by analyzing incident reports provided by transit agencies such as the Toronto Transit Commission (TTC). Using tools from machine learning and queuing analysis, the team was able to recognize factors that have a big impact on the outcome, but which are not always taken into account

“A current strategy might focus the number of buses needed based on the length of the disruption, say 10 buses every 10 minutes,” says Alaa Itani, a PhD candidate in Shalaby’s Transit Analytics Lab. “But it is equally important to consider other factors, such as which routes to pull the buses from, and where to start their initial service.”

Itani gives the example of a real disruption in Toronto in 2015 that affected eight stations and lasted for 60 mins. Her analysis suggested that the buses used in this case were too few and too far away to effectively deal with the disruption. Using more buses from routes closer to the incident could have cut passenger delays and the longest queue at the disrupted stations by 50%.

Even in cases where the number of buses is held constant, being more strategic about which buses were used and where can make a difference. In the above case, Itani’s models suggest that this approach could have reduced total user delays by about 23%.

“There is always a compromise between how far the dispatched buses are and how many riders they would otherwise serve,” says Itani. “If we pay more attention to maintaining that balance, we can get better outcomes.”

Still, Itani says that there are some situations where shuttle buses simply cannot get to the scene fast enough.

“Our analysis showed that while bus bridging can be effective in less congested subway segments, there are places in the downtown core where bus bridging is constrained by the road or curb capacity at the affected subway stations and thus it is not enough,” says Itani.

“In these cases, agencies are recommended to follow supplementary mitigation plans like directing passengers to parallel routes or encouraging passengers to continue their trips using active modes.”

The team has developed two decision support tools to help transit agencies deploy bus bridging more effectively. The first, called DASh-Bus Planner, is designed to help transit agencies assess different shuttle bus deployments and scenarios. The second, called DASh-Bus Optimizer, provides transit operators with a near optimal bus bridging plan in the event of an unplanned rail disruption.

Itani says that not only could these tools help agencies better manage disruptions, but they could also provide strategies to reduce crowding due to ordinary surges in ridership.

“Transit agencies are usually risk averse, so we understand that it may be challenging for them to make the kinds of changes recommended by our tools,” says Itani. “However, the recent pandemic has forced the issue. The disruptions they are currently dealing with could provide an opening for them to re-think their traditional approaches.”

By Tyler Irving

This article originally published by U of T Engineering


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