Exploring a new source of traffic data in the African context
As a transportation engineering lecturer at the Department of Civil Engineering, Dr Megan Bruwer is not an unfamiliar face to the Faculty of Engineering at Stellenbosch University (SU). She consulted in Transportation Engineering and Public Transport Operations before returning to an academic environment as a lecturer and later as a postgraduate student. She is graduating with her PhD in Engineering at SU’s March 2023 graduation ceremony.
Megan found her passion – transportation engineering – during her undergraduate engineering studies. “Transportation engineering is all about human interaction with the built environment, which I find fascinating. It is also the field of civil engineering where you have the most impact on the urban form and social society,” she says.
Her PhD research considered the appropriate use of a relatively new source of traffic data – floating car data or probe data – in the African context. This passive data is collected by GPS devices, primarily smartphones, about trip trajectories and speeds of vehicles.
“I started by considering issues that could impact the data in a low- and middle-income country context, including the sample distribution between social groups, typical urban form, and traffic homogeneity, which are vastly different than in high-income countries. I proved that the sample of probes does impact the accuracy of the data – the first time that a sample bias was investigated and quantified in probe data research,” she explains.
“I then considered how traffic state can be evaluated from probe data, given this bias, and described various appropriate use cases for probe data in South Africa. One of the novel approaches considered a method to find potholes using probe data – a useful tool in our country indeed!”
Megan says the urban form and mobility model in South Africa is highly unsustainable and a pressing challenge facing the transportation industry today. “The poorest population groups are positioned furthest from opportunities and public transport is used only by those with no other option. Our transport infrastructure cannot handle the trip demand that results from these imbalances. We need to evaluate why people choose the trip patterns they do, how our social context and urban form are influencing this choice, and how we should be developing a public transport system that can change our current trajectory of ever-increasing private mobility to a more sustainable mobility paradigm,” she explains.
Balancing her academic, professional and personal commitments while pursuing her PhD was an enormous challenge. “I struggled to find a balance because my academic commitments to my students and teaching will always come first. Just as I found my rhythm, COVID-19 hit!”
In 2021 she was granted study leave, found her stride, and made huge progress on her PhD. “The momentum I had built up in 2021 helped to push me over the finish line in 2022.” Now in her off time she gets to enjoy “just being a mom” to her son, who turns five this year.
Her advice to aspiring civil engineers considering a PhD is to choose a topic that excites them. “A PhD is a long road; you will need the topic you truly want to investigate to pull you through the slow days.”
Megan has exciting projects in the pipeline. “I have developed a research interest in sustainable transport and urban psychology, which will direct much of my future research. My PhD co-supervisor is from a social sciences and psychology background, and I see the enormous need and potential for this type of research in South Africa.
“Our research team also hopes to implement a solution to alleviate some of the congestion on the arterials in Stellenbosch, which we are working on with Stellenbosch Municipality.”
And last but certainly not least, she looks forward to picking up her teaching and learning research again. “I get enormous joy from teaching and working with my students. I hope the feeling is mutual.”
– Dr Bruwer attended the Transportation Research Board (TRB) Annual Meeting in Washington DC, January 2023.
[Article by Amber Viviers]