No one wants to be stuck in traffic, especially not with research showing how detrimental it can be to our health.
Sitting in traffic can also raise your blood pressure, a study out last week found – not out of frustration though, but because of the air pollution drivers inhale.
Nowhere are those health effects felt more acutely, perhaps, than in South Korea, a country thought to have some of the longest average commuting times and highest rates of depression among OECD nations.
A new study of more than 23,000 people has rectified that research gap, finding that South Koreans who commute longer than an hour are 16 percent more likely to experience depressive symptoms than those with shorter commutes under 30 minutes.
Dong-Wook Lee, a public health researcher at Inha University in Korea, and colleagues dug into data on working-aged participants from the Fifth Korean Working Condition Survey, a nationally representative survey conducted in 2017.
Survey participants answered questions based on the five-point World Health Organization well-being index, from which the researchers scored their mental health.
The average daily commute time was 47 minutes. That equates to almost 4 hours of commuting per week if people worked 5 days.
One-quarter of the 23,415 respondents reported experiencing depressive symptoms, judged by their index scores – a far cry from a doctor's assessment or diagnosis of any kind.
Although the study does not show cause and effect, the link between hour-plus commutes and poorer mental health among men was strongest for those who were unmarried, worked more than 52 hours per week, and had no children.
Among females, long commuting times were most strongly associated with depressive symptoms among low-income workers, shift workers, and those with children.
"With less time to spare, people could be short of time to relieve stress and combat physical fatigue through sleep, hobbies, and other activities," the researchers told the Korean Biomedical Review.
While the analysis adjusted for age, weekly work hours, income, occupation, and shift work – all factors that could impact someone's mental health – many individual risk factors for depressive symptoms, such as family history, could not be accounted for.
The national Korean survey data also didn't specify the modes of transport that commuters used. However, switching from driving to active transport such as cycling or walking can boost commuters' mental health, a 2018 study of nearly 4,500 UK survey participants found.
There are some possible upsides to a longer commute that we shouldn't overlook: some commuters describe their long journeys home as a good time to 'switch off' or detach from work.
"The association between long commuting times and worsened depressive symptoms was found to be stronger among low-income workers," the researchers note.
"However, the shift to working from home is occurring more quickly among white-collar and high-income workers" than among low-income ones.
"Reducing travel time and distance through improved transportation may provide a better commuting environment for people and improve their health," the researchers conclude.
The study has been published in the Journal of Transport & Health.