Development and Standards in Denmark

When conducting road work on highways and expressways, the safety of both road workers and motorists is of paramount importance. Recent technological developments have led to significant improvements in safety equipment, with a particular focus on TMA systems (Truck Mounted Attenuators) that function as energy-absorbing units during collisions.

What are TMA Systems?

TMA systems consist of a protection module (typically a truck) equipped with an energy-absorbing unit. These systems are designed to:

• Reduce the severity of injuries to motorists in rear-end collisions

• Minimize the risk of injuries to workers near the protection module

• Absorb the energy of impact and decelerate the colliding vehicle to 0 km/h over a short distance

European and American Standards

Two major standards define the requirements for TMA systems:

CEN/TS 16786 (Europe)

The European standard classifies TMA systems into three speed classes:

• Speed class 50 (50 km/h)

• Speed class 80 (80 km/h)

• Speed class 100 (100 km/h)

Test parameters include impacts with vehicles weighing 900 kg and 2,000 kg at various speeds and angles, including frontal impacts and offset impacts at 10° angles.

MASH 2016 (USA)

The American standard represents an update of previous protocols with stricter requirements:

• Increased weights for test vehicles: small cars from 816 kg to 1,097 kg and pickup trucks from 1,996 kg to 2,268 kg

• Mandatory tests for non-centered and angled impacts

• Test levels with speeds of approximately 70 km/h (level 2) and approximately 100 km/h (level 3)

Requirements for TMA Systems in Denmark

In Denmark, TMA systems for use on highways must have a ready-to-drive weight of at least 10,200 kg when used on roads with speed limits of 90 km/h or higher. This ensures adequate protection at high speeds.

Some important safety requirements include:

• The TMA system must be braked on both front and rear axles when stationary

• Direct communication is required between drivers when using multiple TMA systems

• Safety distances between the TMA system and the work site vary according to lane:

  • 10 meters in the third lane and beyond

  • 60 meters in the first and second lanes (where heavy vehicles travel)

  • 60 meters on expressways

Practical Application for Acute, Traffic-Hazardous Incidents

For acute, traffic-hazardous incidents such as lost cargo, large struck animals, or potholes, two types of barriers can be used:

1. Partial barrier: At least one lane remains open to traffic

2. Total barrier: All lanes in one direction are closed

The choice between these methods depends on several factors, including traffic volume, number of affected lanes, and expected time to complete the task.

Future Perspectives

The development of safety equipment is moving toward increasingly advanced TMA systems with better protection. Denmark is in a transition period where barrier wagons are gradually being replaced by TMA systems to improve safety during road work.

This shift underscores the importance of following international standards and constantly improving safety measures for both motorists and road workers on Danish highways and expressways.