It’s been almost a decade since light-emitting diodes, or LEDs, were first installed on school buses. In that time they’ve moved from the domain of brave and/or well-funded fleets into the mainstream of the pupil transportation industry. Technological advances have lowered the cost and raised the performance of LEDs.
Despite these changes, the majority of school buses on the road don’t have LED lighting, and most new school buses are still being delivered with incandescent lights. Many school bus operators aren’t aware of the differences between incandescent lights and LEDs, and there are still some operators who have never even heard of them. They don’t realize that new options in lighting could prevent maintenance headaches down the road.
A different light
LEDs are a different kind of light bulb. In a regular incandescent bulb, wires inside a glass housing hold up a filament. When electricity runs through the filament, it heats up and gives off light. An LED has no filament or glass bulb. It’s a solid piece of clear plastic with a semiconductor inside. When electricity is run through the semiconductor, it is converted directly to light. Because the process is very efficient, it gives off very little heat and requires only a fraction of the energy of an incandescent bulb. The LED is also more durable because there is no glass or fragile filament to break or burn out.
An LED light is usually made up of multiple individual light-emitting diodes. That’s because each diode doesn’t put out as much light as a single incandescent bulb. LED manufacturers place multiple diodes in a single light to make up the difference. Working together, these diodes produce light that is as bright or brighter than an incandescent bulb.
LEDs first appeared on school buses in brake and tail lights, but they’ve since expanded their use. Warning lights, turn signals and stop-arm lights are all available as LED lighting systems. The only major exterior lights that can’t currently be LED are bus headlamps.
Brighter, faster, safer
Although the minimum legal requirements are the same for both types of lights, LED lights have been found to increase safety margins.
CRS Electronics in Welland, Ontario, which offers a complete line of LEDs and has been manufacturing an LED warning light system since 2000, asks its school bus customers to track illegal pass-bys before and after the warning light systems are installed.
CRS President Scott Riesebosch says the before-and-after difference is a reduction of 70 to 90 percent. “And this is not a flash in the pan,” he says. “It’s a sustainable figure.”
The reason that the company’s LED warning lights are so effective, Riesebosch says, is the flash pattern. It’s designed to stimulate the part of the brain that instinctively senses danger. “Our brains have no choice but to pay attention,” he says, adding that people who illegally pass school buses often are daydreaming or distracted and are not intentionally violating the law.
Wanda Kerns, transportation coordinator at Manassas Park (Va.) City Schools, has only a few buses with LED lights in her fleet. But she is a great admirer. “I love them,” she says. “You can see them for what seems like a mile, even in inclement weather. They’re great.”
When it comes to brake lights, LEDs are actually faster to light than incandescent bulbs. When a driver steps on the brakes, electricity shoots through the lighting system. With an incandescent bulb, the filament has to heat up before it produces light. The delay on an incandescent bulb is approximately 250 milliseconds, and while that may not seem like much time, for a car traveling 65 mph, it equates to an extra 24 feet of stopping distance.