Is Trailer Visibility the Missing Piece in Highway Safety?

The trucking industry is currently debating a major safety proposal: side underride guards on semi-trailers.

These steel barriers are designed to prevent passenger vehicles from sliding underneath trailers during certain side-impact crashes. Safety advocates believe they could reduce fatalities in some situations.

At RoadLites, we believe there is an important question being overlooked:

What if the real issue isn’t underride — but trailer visibility?

Many crashes involving semi-trailers occur because drivers do not see the trailer in time.

This is why the conversation around trailer visibility lighting is becoming increasingly important in the trucking industry.

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What Are Side Underride Guards?

Side underride guards are metal structures mounted along the sides of trailers. Their purpose is to stop passenger vehicles from sliding underneath a trailer during certain types of collisions.

While they can provide protection in specific crash scenarios, they also come with major operational and financial challenges.

Challenges of Side Underride Guards

Industry and government analyses have identified several issues with large-scale deployment of side underride guards:

High Cost

Nationwide implementation across the U.S. trailer fleet is estimated to cost between $970 million and $1.2 billion.

Added Trailer Weight

Side underride guards can add 450–800 pounds to a trailer, which can impact:

• Payload capacity

• Fuel efficiency

• Maintenance costs

Complex Installation

These systems require heavy structural installation, making them difficult to retrofit onto existing trailers.

Operational Limitations

Side underride guards may interfere with normal trailer operations, including:

• Loading docks

• Rail crossings

• Uneven road surfaces

• Existing aerodynamic side skirts

Most importantly, underride guards are designed as crash mitigation technology.

They help reduce injury after a crash has already occurred.

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The Trailer Visibility Problem

A major factor in many highway crashes involving trucks is limited trailer visibility, especially at night.

Semi-trailers can be difficult for passenger vehicles to see due to:

• Low side lighting

• Long trailer length

• Poor weather conditions

• Dark highway environments

• Distracted driving

When drivers fail to recognize the presence or full length of a trailer, they may not have enough time to slow down, change lanes, or avoid a collision.

This is where trailer visibility lighting can play a critical role.

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Trailer Visibility Lighting: A Preventative Safety Solution

Instead of focusing solely on crash mitigation, many fleets are exploring preventative safety technologies that improve trailer visibility.

Trailer side lighting systems, such as side skirt lights and outline marker lights, are designed to make trailers visible from much greater distances.

These lighting systems help:

• Improve side visibility for approaching vehicles

• Highlight the full length of a trailer

• Increase awareness during lane changes and turns

• Make trailers easier to see at night or in poor weather

Unlike heavy structural guards, visibility lighting is also lightweight and easy to retrofit onto existing trailers.

A typical lighting setup adds only 1–5 pounds of weight and can be installed quickly without major modifications.

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Crash Mitigation vs Crash Prevention

Both approaches aim to improve highway safety, but they address different stages of a crash scenario.

Side underride guards

• Focus on reducing injuries during a crash

Trailer visibility lighting

• Focuses on preventing crashes before they happen

For trucking companies and safety professionals, improving driver awareness and trailer visibility can be one of the most practical ways to reduce accidents on the road.

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Why Trailer Visibility Matters for Highway Safety

Every year, thousands of crashes involve large trucks and passenger vehicles. Improving trailer visibility at night and in low-light conditions can help drivers identify hazards sooner and react faster.

When a trailer is easier to see, drivers have more time to:

• Slow down

• Change lanes

• Maintain safe following distance

In many situations, visibility can prevent the crash entirely.

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RoadLites: Making Trailers Impossible to Miss

At RoadLites, our mission is simple: improve trailer visibility and highway safety.

As a company built by trucking professionals, we understand the real-world conditions drivers face every day — dark highways, bad weather, long distances, and unpredictable traffic.

Our side skirt lighting and outline marker lights are designed to help fleets increase trailer visibility while adding minimal weight and cost.

Because in trucking safety, the most effective solution is often the one that helps prevent the accident from happening at all.

Visibility is the first line of safety.