Road safety, tyres and related issues
Vehicle Safety Systems have developed since the introduction of vehicles on the market.
These systems are installed to promote the safety of vehicle, occupants, road furniture and other road users.
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A safety system could be active or passive.
Active safety systems reduce or prevent the occurrence of accident, while passive systems reduce the effect of accident.
Mirrors, Antilock Brake System (ABS), Vehicle Stability Control (VSC) are examples of active systems.
Some passive safety systems are Seatbelts and Airbags.
However, one important active safety component of the vehicle, which is normally overlooked by many vehicle users is the tyres.
Vehicle manufacturers therefore developed Tyre Pressure Monitoring System (TPMS) to monitor the pressure in the tyres.
However, TPMS is not a replacement or substitute for regular tyre checks and good tyre maintenance practices.
Tyres
A tyre is considered one of the most important parts of a vehicle.
This is largely due to the fact that it affects many of the vehicle performance factors such as traction, motion, fuel consumption, braking, load support and comfort.
Additionally, a tyre failure or “blow-out” during driving poses serious safety issues.
A tyre is like your shoe/foot.
It is the only contact between the vehicle and the road.
Most vehicle owners do not wear oversize/undersize, torn, cut and worn-out shoes but are comfortable using the wrong size, improperly inflated, cracked, cut, worn out and expired tyres.
Tyres with the above characteristics may be described as defective tyres.
A defective tyre may lead to loss of control of vehicle, increased braking distance, risk of aquaplaning/losing grip due to wet road (building up of water between your tyres and surface of road), leaking tyres, flat tyres or the most serious situation of a tyre failure or “blow-out/burst” while driving.
The nature of wear of a tyre is an indication of weak suspension components, tyre under or over inflation, wheel misalignment, unbalanced tyres et cetera.
It is recommended that tyres have an average life of six years from the date of manufacture but should not be used after 10 years.
Most tyres are made from rubber which could be solid rubber tyres without air or pneumatic tyres (rubber with air).
Solid rubber tyres are normally used in vehicles such as tractors, forklifts which work in areas with high risk of puncture.
However, most vehicles use pneumatic tyres.
Pneumatics tyres are generally preferred for vehicles since they are lighter, have better shock absorption capacity and give a smoother comfort.
Tyre has rating/specification/marking on the sidewall.
They include but not limited to size, trademark name, traction rating, load capacity, speed capacity, recommended pressure, Tire Identification Number (TIN) which includes date of manufacture, tread wear and temperature rating.
For example, in the diagram below, the treadwear rating of 220 indicates that the tyre will wear about twice (precisely 2.2 times) as long as the control/reference tyre which is assigned 100.
Also load and speed rating 95H indicates a load rating (95) and speed rating (H), respectively.
This determines the maximum load and speed capacity of the tyre which is obtained using a chart.
In simple terms, vehicle manufacturers have determined your maximum speed and load by the original type of tyres under your vehicle!
However, the life span of tyres is largely dependent on storage conditions and usage.
Cracked/cut, badly worn-out tyre
In Ghana, the National Road Safety Commission (now National Road Safety Authority (NRSA) in 2015 estimated that defective/substandard/bad tyres increase the risk of accident occurrence by 30 per cent and 15 per cent of vehicles involved in accidents had some form of tyre defect prior to the accident (https://www.graphic.com.gh/news/general-news/ban-on-use-of-substandard-tyres-effective-sept-1.html).
The Road Traffic Regulations, 2012 (L.I. 2180) prohibits the use of tyres more than four years, tyres rated temperature class C, tyres with tread depth less than 1.6 metres, worn out tyres, under and over inflated tyres among other provisions.
Tyre Labelling Information
There are international regulations governing the labelling of tyres according to parameters such as fuel efficiency/rolling resistance, wet grip/braking performance and external noise emission.
Fuel efficiency/rolling resistance and wet grip/braking performance are generally rated alphabetically from A (green) and G(red) while external noise is in decibels (dB).
A (green) being the most efficient or highest grade and described as an “Eco or green tyres”.
The labelling is similar to that of home appliances such as refrigerators.
For example, a labelling of A for fuel efficiency means the tyre is most fuel efficient.
In 2020, for example, The European Union (EU) passed new regulations on the labelling of tyres with respect to fuel efficiency/rolling resistance, wet grip/braking performance and external noise emission.
According to the regulation, the EU road transport sector was responsible for about 22 per cent total emission of greenhouse gas emissions in 2015.
However, tyres also contribute to between 20 to 30 per cent of the fuel consumption of vehicles.
Therefore, fuel efficient tyres or “Eco or green tyre” will lead to a significant decarbonisation and reduction in the greenhouse gas emissions in the transport sector.
Additionally, fuel efficient tyres are cost effective due to savings on fuel which offsets the higher purchase cost.
Furthermore, information on the wet grip parameters and noise of tyres improves road safety and the effect of traffic noise on health significantly.
Conclusion
The need for countries to enact and enforce regulation on rating/specification and labelling of tyres cannot be overemphasised.
This will enable them to reap the several benefits including reduction in fuel consumption and importation of petroleum products, significant decarbonisation and reduction in greenhouse gas emissions, reduction in accident, improvement on road safety and reduction in traffic noise.
Ghana must therefore take advantage of such a regulation to reap the above benefits for the promotion of economic development and good health for the people.
Recommendations
• The review of Road Traffic Regulations, 2012 (L.1. 2180) to include tyre labelling information on fuel efficiency/rolling resistance, wet grip/braking performance and external noise emission.
• The importation of only tyres with higher/efficient rating and labelling into the country.
• Training and education programme by National Road Safety Authority (NRSA) and Driver and Vehicle Licensing Authority (DVLA) for Tyre Importers, Tyre Dealers, Vehicle Dealers, Vulcanisers, Commercial Driver Unions, Organisations and general public on tyre rating, labelling, maintenance and storage.
•Organisations and individuals must ensure regular maintenance of tyres such as daily checks, inflating tyres to recommended vehicle manufacturers pressure, checking wheel alignment, tyre balancing, wear, cracks and manufacturing/expiry date.
•Regular calibration of tyre pressure gauges of Vulcanisers by Ghana Standards Authority (GSA).
• Inspection of tyres by Motor Traffic and Transport Department (MTTD) and DVLA.
The writer is an Engineer,
Ghana Highway Authority.
E-mail: [email protected]