Heavy lorries must have a speed limiter installed and sealed, and special, lower speed limits apply to lorries and articulated vehicles. Here are the rules — limiter adjustment, sealing and tampering, and speed limits in town, on main roads and motorways.
Introduction
A heavy vehicle has a long stopping distance and large kinetic energy — the energy grows with the square of speed. Therefore, lorry speed is limited in two ways: technically with a speed limiter in the vehicle, and legally with special speed limits in the Traffic Act.
Speed limiter
The limiter intervenes in engine management so no more fuel/power can be supplied when the set speed is reached. The fixed value (90 km/h for goods vehicles) is set lower than the physically possible maximum speeds precisely to reduce the severity of accidents and even out traffic speed.
Sealing and manipulation
The speed limiter must be sealed so the setting cannot be changed, and the installation is documented. Removing, bypassing, or altering the limiter — or manipulating the tachograph to hide excessive speed — is a serious violation that can result in fines and orders to remedy. The limiter's function is checked during roadworthiness tests and roadside checks.
Members only
The rest of the article is locked
Create a free user account to unlock all articles, calculators, templates and range — and get access to quizzes and classes. It takes less than a minute: name, email and a password. No payment card.
Want to try something first? See what you can use without an account — the junior zone, the encyclopedia, the videos and more.