Public transport availability, delayed learning to drive and later life car dependence
Abstract
High levels of car dependency are a major challenge for decarbonisation policy. This paper explores how early-life mobility environments shape long-run driving behaviour through two underexplored questions: whether public transport access predicts delayed learning to drive and whether the age at which individuals learn to drive is associated with later driving intensity. We merge nationally representative survey data from Ireland (N > 2,000) with Public Transport Accessibility Level (PTAL) scores to model (1) age at learning to drive, using survival analysis, and (2) recent driving behaviour, using a hurdle regression model. Higher public transport accessibility is associated with significantly later learning, with individuals in high‑PTAL areas 30% less likely to have learned by age 20 than those with no access. Each year of delayed learning predicts a lower likelihood of weekday driving and a 2% reduction in Vehicle Kilometres Travelled (VKT) on driving days. The findings have implications for understanding the long-term benefits of public transport provision.
Non-Technical Summary
Road transport is one of the largest contributors to greenhouse gas emissions and reducing car dependence is central to meeting climate targets. Yet most efforts to understand car use focus on current behaviour. Much less attention has been paid to earlier life stages, when people first begin forming travel habits. This study asks whether public transport affects when people learn to drive and, in turn, whether the timing of learning to drive has long‑term consequences for how much they drive in later life.
To investigate this, we combined data from a large national survey in Ireland (of more than 2,000 people aged 16 and over) with detailed information on public transport accessibility. We examined two questions:
- Does better public transport increase the likelihood that people delay learning to drive?
- Does delaying learning to drive result in less driving as people progress through adulthood?
We found that people living in areas with good public transport learned to drive significantly later. In places with no effective public transport, almost six in ten people began learning to drive by age 20. In areas with high-quality service, the figure was four in ten. This means that improving public transport may slow the early rush to driving and give young adults more opportunities to experience other transport modes.
We also found that people who had learned to drive later are, now, less likely to drive on an average weekday, even accounting for their current public transport access. On days they do drive, they drive less. Over a year, we estimate that a person who learned at age 22 drives over 1,500 kilometres less on weekdays than someone who learned at 17. These differences accumulate over a lifetime, implying a meaningful long‑term impact on emissions.
The results are consistent with early adulthood being a formative period for developing travel habits. During this life stage, people may move out, start jobs, form relationships, and build routines. If a person starts this phase already driving, they may be more likely to build their daily life around the car. If they do not drive yet, they are more likely to use and grow comfortable with public transport, cycling, or walking. This can influence later decisions about how to travel.
The results suggest that public transport investments have benefits far beyond the immediate increase in passengers. Improving access can delay the point at which young people start driving, and this delay itself reduces the amount they drive years later. Policies that make public transport cheaper or easier for young people may therefore have lasting effects on long‑term car use.
At the same time, most people in Ireland still learn to drive eventually, regardless of access. This means that car dependence is likely to remain high. Decarbonisation will require continued progress in vehicle electrification alongside better public transport.