Cate MacLeod

Traffic calming measures, cycle paths, and other road safety interventions aim to save lives and promote active transportation — but to understand their impact, we must be able to compare before and after a change was made. That can be challenging because all too often, city records are inaccurate, incomplete, and out of date.

The Data Sciences Institute Catalyst Grant awarded to Professors Brice Batomen Kuimi, Dalla Lana School of Public Health and Marianne Hatzopoulou, Department of Civil and Mineral Engineering, Faculty of Applied Science and Engineering, aims to build a dataset identifying the implementation of traffic calming interventions that can be used for evaluation studies that look at the impacts of these changes. The DSI seed grant awarded to this interdisciplinary team is enabling ongoing collaboration with the City of Toronto and the development of an algorithm that can support the use of Google Street View images to identify where and when changes have occurred.

With hundreds of thousands of images to comb through, manually going through images to look at each street over time to identify when and where traffic calming interventions were implemented is challenging. So, the Eye on the Street team trained a machine learning algorithm to look at images of the same segment from one year to the next to identify when something was implemented.

The team started out with existing techniques from the literature but found that they were affected by data leakage. This refers to connections between the part of the data used for training and the part of the data used for testing that create the impression that a model is working well — but only because it’s repeating what it was trained on.

“In our case,” Prof. Batomen Kuimi explains, “because we have multiple images from the same location, you may end up having an image of the road segment in 2010 in the training and an image of 2017 in the testing. So yes, over the years things might change, but it’s basically the same image. As soon as we made sure that if an image from one location was in the training, no other image from the same location, even in another period, should be in the testing, the result was pretty bad. So we have had to do a lot of work to find other techniques.”

The DSI funding has enabled the development of a new algorithm that tackles this data challenge in a new way, narrowing down the vast number of images to an amount that is manageable for a human to check. For the Eye on the Street team, this means that the algorithm can take Toronto’s 12,000 road segments, over 10 years — more than 120,000 images — and reduce that to 5,000 images where there is a high probability of having an intervention present.

This technique can also be applied in other scenarios. With the approach now described in a published paper and the accompanying code available on GitHub, other researchers are interested in exploring its use for different types of interventions and exposures in the built environment, as well as for impact evaluations with outcomes such as noise and air pollution, where it is essential to know when and where the intervention was implemented.

Prof. Batomen Kuimi says that the algorithm can be especially helpful in cities. “The official records are not always accurate. Sometimes the year of installation in the official documents can be off by one or two years. And depending on what you are studying, it can be really problematic.”

The DSI funding enabled the team to further collaborate with the City of Toronto. As part of the training stage, where images are annotated to say whether or not traffic calming features are present, the team got input from City of Toronto and Transportation Services on how to classify images. The City of Toronto maintains maps of traffic calming measures through the Vision Zero initiative, so the team has been able to compare the model’s findings to the city records. When they compared it to the 2023 vision-zero map they were given at the start of the project, they had found a lot more that were missing from the map. But this spring, the city published a new Vision Zero map, and comparing those shows very good agreement, especially for more recent interventions.

“Toronto was already a good student in terms of keeping track on what’s going on compared to other cities. In other cities in Canada, it would be very helpful to use this type of technique.”

Gary Bader, DSI Associate Director, Research and Software adds, “DSI seed funding supported this project to solve an impactful data science challenge. It will be exciting to see its applications in road safety and its potential for helping us understand and address how a city’s built environment affects people’s lives.”

Applications are now open for the 2026 Catalyst Grants.

When a person experiencing hearing difficulties visits a hearing clinic, the assessment may involve listening to simple tones, words, or sentences and repeating them back exactly. These kinds of tests are useful, but they do not fully capture how hearing works in everyday life.

Much of the speech we listen to is continuous — conversations or stories — and we usually remember the meaning rather than the exact wording. Tests that use more naturalistic speech materials can provide a better picture of real-world comprehension difficulties but generating these materials and scoring a person’s responses is challenging and time-consuming without automation.

The Data Sciences Institute Catalyst Grant awarded to Björn Herrmann, a psychologist and cognitive neuroscientist at Baycrest’s Rotman Research Institute and Karen Gordon, an audiologist in the Hospital for Sick Children’s Department of Otolaryngology aims to improve hearing assessment processes through the use of AI. The DSI seed grant awarded to this interdisciplinary team is enabling new applications of large language models (LLMs) to generate naturalistic speech materials for comprehension testing, and to create tools to automate scoring of how well the participant understood what was said.

LLMs can compare the semantic meaning of the text that was played to a participant or patient and the text of what they recalled, assigning a higher recall score when the meaning of the recalled response more closely matches the original. “We can use large language models to identify meaningful units of speech and automatically score how much a listener understood them,” Dr. Herrmann explains. “LLMs can actually be more consistent than if we asked humans to do that kind of task.”

Importantly, LLMs also enable testing participants in their first language, removing the added language-processing effort required of non-native speakers. Speech materials can be generated in the participant’s first language, and their responses can be scored in that same language using a standardized automated approach. This helps ensure that results are comparable across languages, including with English-language assessments.

 “With modern AI-based voices, we can use the same voice across many languages. So, it’s as if one voice actor could record speech materials in more than 100 languages, and a multilingual scorer evaluates comprehension consistently across them,” says Dr. Herrmann.

With the support of the DSI seed funding, the team is collecting data from older adults with hearing aids, who come in and listen to speech in background noise as would be done at a hearing clinic. They do this with and without hearing aids to see if the automated scoring approaches that the project has developed can help tell whether hearing aids help with speech comprehension or not. This will be the first step towards a clinically viable approach.

The team is also working with hearing aid companies. Manufacturers are interested in measuring how well their hearing aids work with more natural stimuli to further improve their products. The team’s findings suggest that hearing aids have more of a benefit with verbatim recognition than with the naturalistic story listening, which is consistent with many people’s experience in their everyday life. Hearing aid manufacturers want to directly test verbatim recall versus story-based recall, using these automated tools, to develop better metrics to evaluate hearing aids and how well they work.

“This is an exciting application of AI and data science to address an important health challenge. It’s amazing to see how this innovative work is attracting industry partnerships and moving towards having a clinical benefit,” says Gary Bader, DSI Associate Director, Research and Software.

Applications are now open for the 2026 Catalyst Grants.