During the COVID-19 pandemic, stay-at-home orders in conjunction with working from home, school closures, and event cancellations resulted in a decrease in travel demand. Under normal circumstances, these activities are components of trip chains and utilize a multimodal transport network. The overall performance of the network can be traced through delays in the bus system as buses capture both changes in ridership and fluctuations in mixed traffic conditions. This paper explores the hypothesis that resumption of a single component in trip chains (i.e., school reopening) is sufficient for a measurable change in transport system performance. This study used school reopening in Sydney, Australia as a case study to explore whether school-related trips affected bus system performance directly with higher student patronage or indirectly with heavier road congestion from parental car trips. Both stop dwell times and differences in delays between successive stops were used as bus service indicators. Dwell times reflect the travel demand for buses and delay differences capture local changes in service reliability. We found that increase in ridership had limited impacts on bus punctuality. However, the level of local bus performance worsened after schools reopened, and the effect was more pronounced in commercial areas in the afternoon when schools ended, suggesting secondary trip purposes such as leisure and shopping in addition to school pick-ups. This study revealed the interaction between different trip purposes during the postshutdown period and threw light on changes in travel behavior patterns as travel restrictions were relaxed in pandemic circumstances.