Introduction

Downtime in traffic management is more than just an inconvenience — it can cause significant disruption, compromise public safety, and damage confidence in the reliability of infrastructure. While much attention is paid to the technology inside the systems, it is often the protective housing that makes the biggest difference to long-term performance for the traffic management sector. The choice of enclosure material may seem secondary, but it is an imperative consideration. The right decision can prevent unnecessary failures, while the wrong one can lead to corrosion, maintenance headaches, and ultimately, system downtime.

This blog aims to shed light on the factors that can help prevent downtime and keep your operations running smoothly. 

Why Material Choice Matters

Although outdoor enclosures must meet certain standards, there is no single prescription for which material should be used. Instead, the selected housing must be suitable for the intended application and environment. Traffic management installations face unique challenges, from exposure to rainwater and pollutants to the risk of vandalism or physical damage. For this reason, resistance, durability, and long-term reliability must all be considered before committing to a material.

Stainless Steel

Standard stainless steel enclosures are often intended for indoor use, which can sometimes go unnoticed until performance issues arise outdoors. While stainless steel can be suitable, additional factors must be carefully considered, such as IP protection class, air temperature and humidity, and secure sealing. Door seals require protection, often with a rainhood, to prevent water ingress.

Ultimately, stainless steel has the potential to work well in outdoor settings, but only with additional design considerations and protections in place.

Aluminium

Aluminium is widely used as a base material for outdoor housing, making it a natural choice for traffic management. Its lightweight properties make it easy to process and handle, while its natural resistance to corrosion provides strong protection. Aluminium also offers protection against electromagnetic interference with the right supporting measures, which is an advantage in high-frequency traffic systems. 

Plastic (Glass Reinforced Plastic, GRP)

GRP has become a particularly desirable option for outdoor enclosures in traffic management thanks to its durability and reliability. Unlike sheet steel, GRP does not rust, making it especially effective in environments where rain, road salt, and pollutants accelerate corrosion. ULF1-rated GRP enclosures are also designed to withstand heat, pressure, and impact, which are all common stress factors at roadside locations.

Beyond corrosion resistance, GRP offers additional advantages:

• Lightweight for safer and easier installation.
• Strong insulating properties (up to 1000 volts for Class 2 protection).
• Minimal maintenance requirements.
• Robust locking systems to deter vandalism and theft.

This combination of protective and practical qualities makes GRP one of the strongest choices for reducing downtime in traffic management applications.

Corrosion Resistance

Corrosion is one of the most common threats to outdoor enclosures. An enclosure that is made of sheet steel will rust and corrode in a relatively short time. Painted sheet steel is arguably the least suitable material for outdoor applications due to its poor corrosion resistance. 

Despite the good corrosive properties that aluminium naturally possesses, this material can still corrode under certain conditions in the environment, producing the so-called ‘white rust’. Outdoor enclosures are often provided with an additional protective coating that is applied at the factory in the desired colour by the user, but this coating must be UV-resistant to prevent chalking. 

By contrast, GRP eliminates this problem entirely as it does not contain metallic properties. This not only extends the life of the enclosure but also avoids costly interruptions caused by corrosion-related failures. Measures like scrutinising material choice will benefit your enclosure and equipment in the long term.

Standards

Corrosion resistance is evaluated according to the standard for empty enclosures. However, in practice, these references are often made to a C3, C4, or even C5 corrosion resistance class.

These classes primarily apply to steel structures, but it is becoming increasingly common to see the C3-C5 corrosion classes also being applied to switchgear, distribution, and control enclosures made of thin sheet metal or aluminium.

In addition to the painted layers, the non-painted parts must also meet this classification. Concerning standard supplier portfolios of painted sheet steel enclosures, a different base material including hinges and lock parts must be used in the majority of cases. A notable element of concern here is the cable entry method, which must not detract from the C-class corrosion resistance. 

Maintenance Considerations

Preventive maintenance is a key factor in avoiding unexpected downtime. Aluminium enclosures may require regular treatments, such as protective coatings, touch-up painting, or even complete restoration if damaged by UV or erosion. Stainless steel and sheet steel also need regular inspections and upkeep to maintain performance.

GRP enclosures, on the other hand, require minimal intervention. A gentle clean with mild detergent is often sufficient, and no extra treatments are needed to maintain their durability. This low-maintenance design ensures consistent protection with less resource investment, further reducing the likelihood of downtime.

Protecting Equipment Life

The choice of enclosure also impacts the longevity of the equipment inside. Outdoor environments expose systems not just to heat but also to the cold and condensation. Solutions such as fans, heaters, and cooling systems can help regulate temperatures, but the integrity of the housing remains a crucial concern.

Traffic management systems may often be temporary — for roadworks, construction detours, or event management — but even short-term installations must safeguard sensitive components. Investing in durable enclosures that can be redeployed across projects reduces waste, prevents failures, and offers long-term cost savings.

Conclusion

Preventing downtime in traffic management systems starts with smart, proactive decisions about enclosure materials. Stainless steel and aluminium both have merits, but their vulnerabilities require extra maintenance and protection. Glass Reinforced Plastic (GRP) stands out as the most resilient option, offering corrosion resistance, durability, ease of handling, and minimal upkeep.

By scrutinising material choices and prioritising long-term reliability over assumptions or short-term cost savings, decision-makers can ensure that traffic management systems remain operational, safe, and efficient, no matter the conditions.