Beacon lights are a central element of traffic safety and play a crucial role in protecting workers and road users in public spaces. This article sheds light on the function, different types, and strict regulations for the use of these warning lights, including their specific applications in the context of mobile heating systems.
Table of Contents
What Is a Beacon Light?
A beacon light is a robust, usually battery-powered or rechargeable signal light designed for mounting on traffic delineators (also called safety beacons) or barrier gates. It is also known as a construction site warning light and in Germany, it must generally comply with the Technical Delivery Conditions for Warning Lights (TL-Warnleuchten) and often also the Technical Delivery Conditions for Delineator Posts (TL-Leitbaken), and be tested by the Federal Highway Research Institute (BASt). Many modern beacon lights use durable LED technology and have an automatic twilight switch that activates the light automatically at dusk.
What Are Beacon Lights Used For?
Their main function is to increase the visibility of barriers. They are used wherever temporary or mobile obstacles in public spaces need to be secured. The primary uses are:
- Securing construction sites: They mark the course of lane narrowings, barriers, and diversions.
- Marking delineator posts: They are mounted on delineator posts used for the longitudinal closure of work areas.
- Barrier gates and fences: They increase the visibility of barrier gates and construction fences that secure, for example, sidewalks or ditches.
- Accident sites: They can be used for quick securing of short-term danger spots.
What Must Be Considered When Using Beacon Lights?
The use of beacon lights in Germany is regulated by the “Guidelines for the Safety of Work Sites on Roads” (RSA 21). Important points for their use:
Legal Basis (RSA 21)
The type of light (flashing or steady), the color, and the spacing must comply with the specifications of the respective standard plan of the RSA 21. For example, for longitudinal barriers on roadways, a maximum distance of 9 meters between the illuminated beacons is often prescribed (Standard Plan B 1/5).
TL-Conformity
The lights must meet the requirements of the TL-Warnleuchten. For mounting on delineator posts, testing according to TL-Leitbaken 97 is often also required, which also concerns the passive safety of the beacon itself.
Mounting
The lights must be mounted firmly and securely on the beacons or barriers. For use as a beacon light, the light must be mounted without the lamp holder bracket to ensure passive safety.
Functionality
Before each use, a visual inspection for defects and a check of the batteries or the battery charge level is necessary to ensure continuous operation throughout the night.
Prohibited Use
The use of delineator posts (and thus also beacon lights) for barriers on sidewalks is generally not permitted according to RSA 21.
When using beacon lights, therefore, legal bases and conformities as well as aspects regarding mounting, functionality, and location of use must be observed.
What Different Types of Beacon Lights Are There?
Beacon lights differ mainly in their technical features and their design:
| Feature | Typical Variations | Application Area |
|---|---|---|
| Light Color | Yellow (standard warning color in Germany), Red (rarer, e.g., for full closures) | Yellow is used for general warning and traffic guidance. |
| Light Emission | One-sided or two-sided | Two-sided lights are required if the barrier must be visible from both directions of travel (e.g., on delineator posts). |
| Light Type | Flashing light (usually 60 flashes per minute) or steady light | Flashing light has a higher warning effect; steady light is for orientation. The choice depends on the standard plans of the RSA 21. |
| Technology | LED (standard, energy-efficient) or older incandescent bulbs | LED lights are the standard today due to their longevity and low power consumption. |
| Testing | TL-tested (according to TL-Warnleuchten and/or TL-Leitbaken) | Testing according to TL is mandatory for use in public road traffic in Germany. |
Why Are Beacon Lights Needed in Connection with Mobile Heating Systems?
Mobile heating systems are often used on construction sites, during heating failures, or for screed drying. These systems are often housed in containers, on trailers, or as large, free-standing units.
If mobile heating systems or their associated components (such as hoses, cables, or mobile tanks) are placed in public traffic areas, on parking lots, or in the immediate vicinity of roadways, they are considered obstacles or work sites.
Beacon Lights Are Then Needed To:
- Mark the heating unit itself
- Secure the barrier of the installation area
- Mark danger spots
In this context, the beacon lights are mounted on barriers around the mobile heating system to ensure compliance with the duty to maintain safety in accordance with applicable guidelines (e.g., RSA 21).
Sources:
Strassenausstatter.de. (seen on 10.10.2025). Bakenleuchte WEMAS Future – BASt-geprüft
Schake.com. (seen on 10.10.2025). Bakenleuchte POWERNOX nach TL
Operating instructions – TL-Warn- und Bakenleuchte Typ „Future“ (PDF)
Markierungsshop. (seen on 10.10.2025). Ratgeber Baustellenleuchte – Alles zu Einsatz und Auswahl
Stvo2go.de. (seen on 10.10.2025) RSA 21: Abmessungen, Abstand & mehr