Spec’ing Strobe Lights for Utility Trucks

Strobes and beacons play a critical role in both worker and public safety, increasing vehicle visibility during roadside operations. But they aren’t all created equal, which means fleet managers must weigh several factors when spec’ing these lights.

First, define vehicle use and environment. Consider the primary functions and operating conditions of your fleet. Then, strategize for multilevel visibility.

“Do not rely on a single light source,” said Matthew St. Peter, associate upfit engineer at Merchants Fleet (www.merchantsfleet.com), a national fleet management company. “Implementing a multilevel lighting scheme creates a larger, more visible vehicle footprint.”

Beacon Characteristics to Assess
Brightness: Brighter is not always better. For nighttime scenes, reducing light intensity once a vehicle is parked can decrease glare and visual chaos. High-intensity lights are more effective during the day when ambient light can wash out weaker signals.

Flash pattern: Faster flash rates are generally seen as more urgent than slower ones. Wigwag or alternating patterns tend to grab attention and help motorists detect other objects more effectively than simultaneous or random patterns. LED technology enables the same light to provide high-intensity strobe flash patterns as well as the low-intensity, slower beacon pattern.

Color: Amber, which generally signifies caution, is used for road maintenance, construction and towing vehicles. The color is highly visible through fog and smoke. Red and blue typically signify police and fire or a higher level of emergency.

Visibility: Light signals are most conspicuous when they are near the driver’s head height, particularly at the scene of an incident. For lights mounted on emergency vehicles, a wide horizontal viewing angle ensures visibility across multiple lanes of traffic.

Consider These Mounting Options
Cab roof: A cab roof provides 360-degree visibility and is ideal for construction equipment, utility trucks, and emergency and other vehicles that must be seen from all directions.

Grille: For a clean installation, compact LEDs can be mounted directly to the grille or bumper.

Side and rear: These configurations prioritize increased visibility from the sides and rear, which is crucial for vehicles stopped on roadways.

Evaluate the Operating Environment
Urban areas: High-intensity strobes are needed during the day to compete with urban light pollution. In low-light conditions, vehicle lighting must be dynamically adjusted to prevent excessive glare, which can distract other drivers.

Night vs. day: A high-intensity strobe that is effective during the day can be hazardous at night if it’s not dimmed.

Weather: Strobe lights must be able to penetrate through precipitation and fog. Certain colors (e.g., amber) are highly visible in adverse conditions. However, excessively bright lights can reflect moisture, potentially intensifying glare.

Durability and Maintenance
LEDs and halogens: LEDs are solid-state components without fragile filaments, making them highly resistant to vibrations, shocks and physical impacts. Halogen bulbs rely on fragile tungsten filaments that can easily break or fail due to engine vibration, impacts from rough roads and other shocks. Gas-discharge tubes are also prone to failure.

Durability: Modern LED strobes are sealed with industrial-grade epoxy and gaskets to create a waterproof enclosure, often rated IP67 or IP68. This keeps out moisture, snow and dust, helping to prevent corrosion and electrical failure.

Maintenance: With a lifespan of up to 50,000 hours or more, LEDs require minimal maintenance beyond occasional cleaning. A modular design allows damaged wires to be replaced without splicing. Halogen bulbs and strobe tubes have significantly shorter lifespans, requiring more frequent bulb replacements and adjustments. Additionally, moving parts in rotating halogen units can wear out.

Performance: LED technology consistently maintains brightness and flash intensity over its long lifespan. Even if some diodes fail, the light can continue to function effectively. Halogen lights sometimes suffer a gradual reduction in brightness over time as filaments degrade.

Life-cycle cost: While LED strobes have a high initial cost, they offer a lower total cost of ownership over their lifetime due to reduced energy consumption and significantly lower maintenance and replacement costs. The higher long-term costs of halogen lights – including frequent bulb changes, increased energy consumption and more maintenance – offset their lower upfront cost.

Regulatory Considerations
Federal regulations: The Federal Motor Carrier Safety Regulations cover lighting and wiring protection requirements for vehicles on federal roadways.

State and local laws: States have limitations on the colors of flashing lights, restricting use of red and blue lights to authorized law enforcement, fire and emergency medical services vehicles. Non-emergency vehicles, such as tow trucks and construction vehicles, are permitted to use specific colors, including amber. Some state and local laws regulate the brightness and positioning of strobe lights.

Industry standards: SAE J845 (omnidirectional) specifies the requirements for 360-degree optical warning lights, such as beacons used on emergency vehicles, with three classes of light intensity. SAE J595 (directional) covers directional flashing lights and includes intensity ratings.

For multistate operations, check the specific laws and ordinances for each vehicle’s operating area. “Determine if the strobe lights are needed for a specific application – like road maintenance, towing or utility work – as this will influence which rules apply,” St. Peter said. “A vehicle compliant in one state may violate the law in another.”

About the Author: Gary L. Wollenhaupt is a Colorado Springs-based freelance writer who covers the transportation, energy and technology sectors for a variety of publications and companies.