Hello! I am postdoctoral researcher at the Northwestern University Transportation Center. I recently completed my PhD from the Northwestern University’s Transportation Systems Analysis and Planning Program in the Department of Civil and Environmental Engineering. My disseration titled Telemobility Through the Pandemic: Longitudinal Tracking, Modeling and Outlook can be found here
My dissertation research addresses the question of the extent to which the COVID-19 pandemic altered the telemobility landscape in the United States; and the implications of these potentially changing trends on mobility and sustainability of our cities. Other areas of research that I have explored in the past include understanding travel behavior and its interaction with social networks, advanced behavioral modeling, big GPS data analysis and freight planning, machine learning applications in transportation, particularly unsupervised learning and ensemble learning models.
selected publications
For whom did telework not work during the Pandemic? understanding the factors impacting telework satisfaction in the US using a multiple indicator multiple cause (MIMIC) model
Tahlyan, Divyakant,
Said, Maher,
Mahmassani, Hani,
Stathopoulos, Amanda,
Walker, Joan,
and Shaheen, Susan
Transportation Research Part A: Policy and Practice
2022
The COVID-19 pandemic required employees and businesses across the world to rapidly transition to work from home over extended periods, reaching what is likely the upper bound of telework in many sectors. Past studies have identified both advantages and disadvantages of teleworking. The pandemic experience offers a unique opportunity to examine employees’ experiences and perceptions of telework given the broad participation duration and extent. While employer strategies will play a major role in defining the future forms and adoption of telework, employee preferences and constraints, such as access to appropriate technology to work from home or the home environment, are also going to be important factors. Using data from a U.S. representative sample of 318 working adults, this study uses a Multiple Indicator Multiple Cause Model (MIMIC) to understand employee satisfaction with telework. The presented model links telework satisfaction with experienced and perceived benefits and barriers related to telework, and hence provide a causal structure to our understanding of telework satisfaction. We also present an ordered probit model without latent variables that help us understand the systematic heterogeneity in telework satisfaction across various socio-demographic groups. The results suggest younger and older aged individuals experienced/perceived lower benefits and higher barriers to teleworking compared to middle aged individuals. The results also suggest a disproportionate impact on Hispanic or Latino and Black respondents as well as on those with children attending online school from home. Accordingly, this study highlights important factors impacting telework adoption that employers and policy makers should consider in planning future work arrangements and policies in a post-pandemic world.
@article{TAHLYAN2022387,abbr={telework},title={For whom did telework not work during the Pandemic? understanding the factors impacting telework satisfaction in the US using a multiple indicator multiple cause (MIMIC) model},author={Tahlyan, Divyakant and Said, Maher and Mahmassani, Hani and Stathopoulos, Amanda and Walker, Joan and Shaheen, Susan},journal={Transportation Research Part A: Policy and Practice},year={2022},selected={true},html={https://doi.org/10.1016/j.tra.2021.11.025},bibtex_show={true}}
[Open Access] Disentangling social capital – Understanding the effect of bonding and bridging on urban activity participation
Tahlyan, Divyakant,
Stathopoulos, Amanda,
and Maness, Michael
Transportation Research Interdisciplinary Perspectives
2022
Social capital is a critical glue for economic and social development in urban areas. Yet, to effectively guide research and practice, there is a need for careful measurement of social capital and how it links to important aspects of urban system functions. This study is aimed at examining the multi-dimensional nature of social capital and the relationship between these dimensions and travel behavior. Prior research has shown connections between stand-alone social capital concepts, such as resources gathered via social networks, with specific aspects of travel behavior. In this work, we expand the definition of social capital to cover separate dimensions, modeled via multiple indicators. Specifically, we make use of over 1400 observations from the Pew Internet Networks and Community Survey dataset to build a Structural Equation Model dividing social capital into two latent dimensions: bonding and bridging to examine the relationship of both these dimensions with discretionary urban activity participation diversity and frequency. Moreover, broader measures of neighborhood and community engagement are included in the model to explain how such engagement can help with the accumulation of social capital. Our results indicate a positive but differential relationship between both social capital dimensions and activity participation. Further, the results also suggest an absence of correlation between bonding and bridging capital, strengthening the hypothesis that social capital is multi-dimensional. In terms of explaining the social capital accrual, we find that while community engagement is positively correlated to bridging capital, no evidence was found for a relationship between community engagement and bonding capital. Further, neighborhood engagement was not found to be associated with any of the social capital dimensions. This suggests that individuals predominantly rely on close-knit and stronger relationships for social/emotional support, while instead, community engagement significantly helps in the accumulation of bridging capital. The result from the study can be used by policy makers to improve transportation planning, management, and community well-being.
@article{tahlyan2022socialcapital,abbr={socialcapital},title={[Open Access] Disentangling social capital – Understanding the effect of bonding and bridging on urban activity participation},author={Tahlyan, Divyakant and Stathopoulos, Amanda and Maness, Michael},journal={Transportation Research Interdisciplinary Perspectives},year={2022},selected={true},html={https://doi.org/10.1016/j.trip.2022.100629},bibtex_show={true}}
In-Person, Pick Up or Delivery? Evolving Patterns of Household Spending Behavior Through the Early Reopening Phase of the COVID-19 Pandemic
Said, Maher,
Tahlyan, Divyakant,
Stathopoulos, Amanda,
Mahmassani, Hani,
Shaheen, Susan,
and Walker, Joan
Consumer reactions to COVID-19 pandemic disruptions have been varied, including modifications in spending frequency,
amount, product categories and delivery channels. This study analyzes spending data from a sample of 720 U.S. households during
the start of deconfinement and early vaccine rollout to understand changes in spending and behavior one year into the pandemic.
This paper finds that overall spending is similar to pre-pandemic levels, except for a 28% decline in prepared food spending.
More educated and higher income households with children have shifted away from in-person spending, whereas politically conservative
respondents are more likely to shop in-person and via pickup.
@article{said2023person,abbr={spendingcovid},title={In-Person, Pick Up or Delivery? Evolving Patterns of Household Spending Behavior Through the Early Reopening Phase of the COVID-19 Pandemic},author={Said, Maher and Tahlyan, Divyakant and Stathopoulos, Amanda and Mahmassani, Hani and Shaheen, Susan and Walker, Joan},journal={Travel Behaviour and Society},year={2023},publisher={Elsevier},selected={true},html={https://doi.org/10.1016/j.tbs.2023.01.003},bibtex_show={true}}
