Speed limiter rules need to be properly managed

The Department of Transport published the 24th amendment to the National Road Traffic Regulations in Gazette No 40420 of November 11 2016, which limits trucks with a gross vehicle mass (GVM) of between 3,500kg and 9,000kg to a maximum of 100km/h from November 11 2016.

This includes the installation of 100km/h speed limiters for all new medium trucks leaving production on December 1 2016. The National Association of Automobile Manufacturers of SA category for a medium truck is 3.5t to 8.5t GVM — this equates to a payload of about 1.5t to 4.5t, depending on cargo-body mass.

There is no regulation for speed limiters on passenger cars and bakkies under 3,500kg GVM, which is why at least one truck manufacturer chose to remove items from its vehicles to ensure it remains beneath the weight threshold and so does not require a speed limiter.

For over 9,000kg GVM or over 9,000kg gross combination mass, the 80km/h speed limit for goods vehicles remains, with 80km/h speed limiters installed from December 1.

All trucks under 9,000kg GVM must carry the 100km/h speed limit decal on the rear body. Any homologated bus is allowed to do 100km/h even if it exceeds 9,000kg GVM.

This will have an impact on trip times, especially in volumerelated, express freight and courier operations.

There are considerable benefits to adhering to the 100km/h limit. One is fuel consumption. Isuzu Trucks claims that sticking to the 100km/h speed limit can lead to a fuel saving of 5.0l/100km in its NPR 300 AMT.

Trip times increase, but not at the expense of driver fatigue if the round trip is taken in two stages and not in a dangerous single-stage return journey.

Other benefits include reduced brake wear and reduced stopping distance. The latter is vital to improve road safety. There are other benefits, such as more safety for passenger cars and bakkies that should not compete when overtaking with a large 9t GVM medium truck at 120km/h.

There are some things that need to be addressed though. One is the expectations of drivers, who may believe that driving hard against 100km/h will preserve previous trip times. It is a high average speed that counts, not a high top speed. This may initially result in drivers attempting to free-wheel out of gear on long downhills.

FREE-WHEELING

Free-wheeling is extremely dangerous and must be strictly forbidden and disciplined. Freewheeling can also result in engine over-revving

Another issue is that of trucks driving too closely in convoy at the maximum permissible speed, which could prevent other road users from safely overtaking.

Proper driver training and law enforcement will be essential to ensure that these new regulations are managed in a way that not only improves road safety but also helps the truck operators.

THERE ARE MANY BENEFITS TO ADHERING TO THE 100KM/H LIMIT. ONE IS FUEL CONSUMPTION