The braking distance of a lorry is a key aspect of road transport safety. For professional drivers and other road users, understanding how long it takes for a lorry to brake can be a matter of life and death. This parameter depends on many factors that require detailed discussion.
From this article, you will learn:
- What is a truck's braking distance and how is it measured?
- Factors affecting a truck's braking distance
- What is the braking distance of a lorry? – example figures
- Truck braking systems – brake assist systems in modern vehicles
- How to maintain optimal truck braking distance?
- Legal aspects of the efficiency of a truck's braking system
- Braking distance for lorries – specific considerations when braking vehicles with trailers
What is a truck's braking distance and how is it measured?
Braking distance is the distance a vehicle travels from the moment the braking system is activated to when it comes to a complete stop. In the case of lorries, this parameter is significantly greater than in passenger cars, which is primarily due to the greater weight of these vehicles. It is worth distinguishing between several concepts relating to stopping a vehicle – these include:
- reaction distance – the distance travelled from the moment the hazard is spotted until braking begins (depending on the driver’s reaction time);
- braking distance – the distance from the start of braking to a complete stop;
- stopping distance – the sum of the reaction distance and the braking distance.
A lorry’s braking distance depends to a large extent on the vehicle’s technical condition, particularly that of the braking system. A modern braking system in a lorry is a complex system that has to cope with stopping even several dozen tonnes of weight.
Factors affecting a truck's braking distance
The braking distance of a lorry depends on a number of factors, including:
- Vehicle and load weight . The heavier the vehicle, the greater the inertia, and consequently, the longer the braking distance. A fully loaded lorry will brake much longer than an empty vehicle.
- Speed . The relationship between speed and braking distance is not linear, but quadratic. This means that doubling the speed quadruples the braking distance! This is why it is so important for lorry drivers to observe speed limits.
- Road surface and weather conditions . On wet roads, the braking distance of a lorry increases by about 40-60% compared to dry roads. On an icy road, it can be up to 10 times longer!
- Technical condition of the braking system . Efficient brake system parts from SCANIA or other brands are essential for safety. Worn brake pads or discs, problems with the pneumatic system or ABS can drastically increase the braking distance.
- Tyre condition . Tread depth, tyre pressure and tyre type also significantly affect braking performance. Winter tyres on slippery surfaces can reduce braking distance by up to 30%.
What is the braking distance of a lorry? – example figures
The approximate braking distances for a lorry under various conditions (for a fully loaded vehicle weighing 40 tonnes) are as follows:
- 50 km/h, dry surface: approx. 30-35 metres,
- 50 km/h, wet surface: approx. 45-55 metres,
- 80 km/h, dry surface: approx. 80-90 metres,
- 80 km/h, wet surface: approx. 120-140 metres.
Please note that these are approximate values and the actual braking distance of a lorry may vary depending on the factors mentioned above. Furthermore, the above data only takes into account the braking distance, without the driver's reaction time.
Truck braking systems – brake assist systems in modern vehicles
A modern truck braking system is equipped with a number of advanced electronic systems that significantly improve braking efficiency:
- ABS (Anti-lock Braking System) – prevents the wheels from locking during braking;
- EBS (Electronic Braking System) – electronically controls the braking force on individual wheels;
- ESP (Electronic Stability Programme) – electronic stability control;
- AEBS (Advanced Emergency Braking System) – an automatic emergency braking system.
High-end DAF parts or SCANIA parts, trucks feature these advanced technological solutions, which can reduce braking distance by up to 20-30% compared to older vehicles.
How to maintain optimal truck braking distance?
To ensure the shortest possible braking distance for a lorry, the following are necessary:
- regular technical inspections at a professional DAF servicing or other brand;
- checking the condition of the braking system before each journey;
- replacement of worn components with original parts;
- adaptation of driving technique to road and weather conditions;
- compliance with the rules for the correct loading of vehicles.
Remember that investing in high quality truck parts, is not only a matter of efficiency, but above all of safety. The braking system in a lorry is the most critical system in the vehicle, so it is not worth skimping on its maintenance.
Legal aspects of the efficiency of a truck's braking system
The law clearly specifies the requirements for the efficiency of the braking system in heavy goods vehicles. A faulty braking system can result in :
- the registration certificate being confiscated during a roadside check;
- high financial penalties for the driver and the company;
- criminal liability in the event of an accident;
- problems with vehicle insurance.
Regular inspections offered by an authorised SCANIA service or other brand will help you avoid these problems. It is also worth noting the difference between the braking distance of a passenger car and a lorry:
- a passenger car (1.5 tonnes) travelling at 80 km/h will come to a stop after travelling approximately 30-35 metres on a dry surface;
- a lorry (40 tonnes) travelling at the same speed needs about 80-90 metres.
This disproportion shows how important it is for car drivers to keep a safe distance behind lorries and why lorry drivers must be particularly careful and anticipate situations on the road.
Braking distance for lorries – specific considerations when braking vehicles with trailers
Braking a tractor-trailer combination poses additional challenges. Braking system components from DAF or other brands must be perfectly synchronised to prevent phenomena such as:
- the combination "folding" during braking,
- uneven braking on individual axles,
- load shifting affecting vehicle stability.
Modern braking systems are designed with these challenges in mind, offering advanced braking synchronisation systems between the tractor and trailer.
What is the braking distance of a lorry? As you can see, there is no single simple answer to this question. The braking distance of a lorry depends on many variables, including vehicle weight, speed, road conditions and the technical condition of the braking system. For professional drivers, it is most important to understand these relationships and adapt their driving style to the capabilities of the vehicle. For transport companies, it is crucial to service their fleet regularly and invest in quality spare parts. Remember that road safety is the responsibility of every road user. Understanding the limitations of a lorry's braking distance helps all drivers make better decisions on the road and avoid potentially dangerous situations.