Taxi Driving – Pot holes, humps and bumps. How much vibration exposure time is safe?

Much is said about what should be the safe allowable driving time for a Taxi driver. How about checking the driver’s exposure to vibration?

Summary of measured results

Advisable safe exposure (driving) time limit following ISO 2631-1

8 hours 40 minutes per day for 5 days per week.

Total 43 hours 20 minutes per week.

Health and safety advice to Taxi Drivers

Avoid potholes and bumps as much as possible.

Try to have a 5 minute walk every hour or so, in addition to your longer rest time. Try not to rest in your vehicle as sitting restricts blood circulation, particularly to your legs, do slow exercises for your back a few times per day.

Longer Read - 3 minutes

Exposure to vibration is a recognised factor contributing to driver discomfort and pain and has been shown to adversely affect overall well-being in the short term.  Over time, it also leads to several serious health conditions, particularly if vibration exposure is severe.

The domino effect of ongoing discomfort, pain or lack of well-being is the risk that the driver may turn to excessive use of pain relief medication, alcohol or other substances.

To get a measured indication of what exposure a taxi driver in Malta experiences, a Y plate taxi driver was kindly asked to perform their work day, whilst sitting on a vibration measurement pad that is specially designed for such tasks. A big thanks for his support in this, as we hope the information may guide and help others in this work.

Road vibration (quality) map showing the most driven roads in this measurement. Red being high vibration.

Assessment following ISO 2631-1:1997.

Summary of measured results

Vehicle – Ford Focus

Date measured 21 August 2025

Location: Malta

Measurement time is total seated time: 12 hours 26 minutes including seated non driving time.

Distance covered 264 Km

Vibration dose in VDV – 9.272 m/s^1.75 dominant axis Z (spinal direction)

Advisable safe exposure (driving) time limit following ISO 2631-1 (ALV 8.5 m/s^1.75)

8 hours 40 minutes per day for 5 days per week.

Total 43 hours 20 minutes per week.

Acceptable exposure time limit in accordance with VDV limits set in EU Directive 2002/44/EC (ALV 9.1 m/s^1.75)

11 hours 18 minutes per day for 5 days per week.

Total 56 hours 30 minutes per week.

Exposure above ISO ALV limit is considered a CAUTION ZONE.  It does not signify an immediate severe hazard, it means that some action should be taken to lower it, such as better roads, better seats, better suspension, slower driving, less driving, etc.

If one has a conversation with local taxi drivers about their well-being, it is quite eye opening. A number suffer from quite a few conditions including musculoskeletal conditions typically associated with occupational vibration exposure. It may look like an easy sedentary job but it is not.

One cannot but note the corelations with ISO-2631-1 safe limits, in that most of these drivers work far more hours than advisable through such measurements.

On roads, the biggest factor in causing or reducing vibration is road quality, particularly road repairs and damages.

Vehicle suspension, maintenance and seating are the next items that help in reducing the impact from jolting.  Not every car is designed to be used as a Taxi.

Slower driving is the next technical option for reduction, but not the desired one by customers.

Less traffic inherently implies faster driving and thus increased vibration which is undesirable.

The hazardous Exposure Limit Values set out in ISO 2631-1 and EU Directive were NOT reached in this measurement.

NOTES

The purpose of this measurement is to inform and increase awareness.

There may be other considerations besides vibration that impact driver well-being.

Other vehicles will give other results.

The limits and methods set out in ISO 2631-1 are based on decades of research and ongoing study by numerous scientists across the globe.

The limits set out in EU Directive 2002/44/EC are inspired by the ISO 2631-1 but without any scientific study.  The lower (ALV) limits work quite well when applied correctly using the logic specified in ISO2631-1.  The higher (ELV) limits are horrendously high, evidence initself that there is no scientific study supporting them.

If the logic specified in ISO 2631-1 is modified or not followed correctly, the vibration exposure could be grossly underestimated.  This could expose drivers to severe doses together with the inherent long term severe health risks.

Case in point, if this Taxi measurement, was calculated incorrectly, using R.M.S. vibration measurements, this would result in permitting 24 hours driving per day, whilst sill calling it legally safe from an occupational whole-body vibration exposure standpoint.

Taxi driving vibration exposure is a real concern. Road quality, in terms of vibration and jolt reduction for drivers is a cause for concern in all countries. Many have gone as far as redesigning speed bumps and humps to take care of all drivers, be it taxi, van, bus or any other vehicle.

Aldo Calleja

Audiologist - BSc (Hons)

CPCM Reg: 16

www.beacon.com.mt

Beacon Healthcare Ltd.