New research tests city buses for vibration levels
A team of UTS researchers have measured just how bumpy a city bus ride is.
The study measured the vibrations and sudden movements frequently experienced by bus passengers during starts, stops, and turns, especially in urban traffic conditions. Photo: Adobe Stock.
UTS Professor of Risk Management and Injury Prevention David Eager has led a research investigation on the types of movement passengers encounter during bus rides on Sydney CBD routes.
The researchers measured acceleration in different directions, including stops, starts, and turns in urban traffic conditions. These movements can be more noticeable and potentially uncomfortable compared to other forms of transport.
We wanted to measure these vibrations because they have the potential to affect passenger comfort and even contribute to long-term health issues.
Professor David Eager, UTS Professor of Risk Management and Injury Prevention
The researchers discovered that average seat acceleration during bus operation was about 0.12 times the force of gravity, with peaks reaching up to 0.44 times gravity.
This level of vibration can lead to discomfort for passengers, particularly those with pre-existing health conditions such as muscle weakness or spinal issues.
Dr Anna Lidfors Lindqvist, a lecturer at the School of Mechanical and Mechatronic Engineering at UTS and co-author of the study, said that one of the key metrics measured was ‘jerk’.
“Jerk is what you feel when the bus brakes or accelerates. It’s the rate of change in acceleration, and if it's done very quickly, you may feel it like a jolt where your body is pushed forward or backward in your seat.
“If you have been on a city bus, you have likely experienced this due to sudden changes in traffic or when a bus stops or starts to pick up passengers.
“Research suggests that jerk might be a better indicator of passenger discomfort than just measuring acceleration alone,” said Dr. Lidfors Lindqvist.
While the findings may not surprise regular bus users, the study provides valuable data that can serve as a baseline for future improvements in bus design and operation.
This research opens up possibilities for future collaboration between engineers, city planners and health professionals to better prioritise passenger wellbeing.
