It is the last thing that the knowing speeder or driver who had one too many wants to see in his rearview mirror - the pulsating police lightbar. Through the evolution of rotating beacons to strobing LEDs, lightbars are a critical component of the police fleet.
LED lightbars are changing the industry, says Howard Berke, senior vice president of sales and marketing for the Whelen Engineering Co. in Chester, Connecticut. "They offer so many advantages," he enthuses. "They're more reliable and long-lasting."
By comparison, an average incandescent bulb operates for 300 to 500 hours, while a 1-watt LED diode - typically used in lightbars - has a lifespan of more 100,000 hours over 11 years of continuous use.
LEDs also have a tight color range compared to halogen or strobe, producing a brighter and truer color. "You get redder reds, bluer blues and the color doesn't wash out in bright sunlight," says Berke. "The diodes today have a light output equal to or even higher than halogen or strobe bulbs."
LED lightbars can be programed to flash in various, and sometimes synchronized, patterns, "which means you can give a different outward performance for each kind of police action, such as a pursuit or controlling an intersection," Berke explains. "At Whelen, we call these 'scenes,' and the latest lightbar we've come out with can program as many as one or two dozen 'scenes.' "
LED lightbars also draw less power from the battery than halogen or strobe. Berke explains that in the past, most loaded lightbars drew between 30 and 50 amps, which could be - especially in the case of a halogen rotating lightbar - a significant battery-drain. Often, if the lightbar was running, it would be necessary to leave the vehicle turned on even while stopped, or to install a larger aftermarket alternator or secondary battery if the vehicle carried a lot of electronic equipment. In comparison, LED bars draw only 5 to 10 amps, eliminating this concern.
LED bars are tougher, too, according to Phil Von Tom, director of business development for SoundOff Signal, in Hudsonville, Michigan.
"LED lightbars are immune to vibration, whereas strobe and halogen bars take a real beating - the filaments take a real beating," he says. "In terms of maintenance and repair, the LED bar is much more bullet-resistant, and its control boards will run its own diagnostics and tell you where the trouble is."
All of these qualities, in particular the energy-saving aspects of LED bars, are why agencies are trending away from strobe and halogen lightbars, he says.
"There are agencies still running strobe and halogen, but only because it's hard for them to maintain a mix of product," Von Tom says. "But as bids come up, these agencies will transition over to LED lightbars."
Such a transition is taking place at the Virginia State Police, according to Wayne Cosner, garage manager. With 2,600 vehicles in its fleet, changing from strobes to LED bars is not going to be an overnight thing; they are phasing them in as additional lights are purchased. Although Cosner says their strobes have served them well and that many are still performing like new, he describes LEDs as a "no-brainer" decision.
"There are both mechanical and tactical reasons to change over," he explains, listing low current draw, low maintenance, long service life, greatly increased light output, and a tremendous increase in visibility and safety as highlights.
"Without looking at statistics, I would guess we have as many severe patrol vehicle crashes when our vehicles are parked as when they are moving," says Cosner. "We owe it to our troopers to give them the best lighting possible for their protection.
"Strobes are from the 80s and 90s; LEDs are the future," he adds. "Comparing strobes to LEDs is like comparing a Piper Cub to a Learjet."
With 3,500 vehicles in its fleet, the Texas Department of Public Safety in Austin began its conversion to LED lightbars in 2002 and expects to complete this effort by this year, says fleet manager Jerry Newbury.