It has happened to many a bicyclist: the car beside you suddenly cuts into your path or passes close enough for you to feel the heat of its exhaust on your leg.
A big part of avoiding those close calls is being noticed, but for years bicyclists' only defenses were bright clothing, battery-powered incandescent bulbs and the cheery ching-ching of a traditional bicycle bell.
Now that's changing. Thanks to improved LED lights, microchips and smartphone technology, bicycles can have loud horns, brake lights, turn signals and all manner of lighting.
One gadget, called Loud Bicycle, can even make a bike honk like a car.
Jonathan Lansey, a bike commuter in the Boston area, said he yearned for an effective sound to warn drivers that he was in their blind spots. Traditional metal bells lack volume, he said, and yelling can make matters worse with aggressive drivers.
So Mr. Lansey came up with what is basically a car horn on a bike. It's about six inches across and attaches to the stem of the handlebar or one of the central bike frame tubes. The best part is that it has the two-toned sound of an oncoming sedan.
"It is speaking drivers' language," Mr. Lansey said. "They just react right away. If you hear this horn you're not going to think, 'I'll continue backing out of this driveway.'"
Mr. Lansey raised more than $52,000 on Kickstarter, the social fund-raising site, and hopes to be up and running in August. In the meantime, pre-orders are available for $95.
For cyclists who want the volume of a car horn but don't want to scare nondrivers, there is the Orp Smart Horn, another Kickstarter project that will be available to consumers in October.
The horn, which fits on the handlebars and includes a light that pulses with each beep, has a switch that emits a friendly three-toned melody for use on trails bikers share with pedestrians. For the mean streets, however, it has a louder, high-pitched electronic sound, closer to the toot of a Vespa scooter. It will cost about $50, said its creator, Tory Orzeck, of Portland, Ore.
There has also been a surge in bike lighting products of all kinds.
A hand grip by Velo, for example, comes with lights at the end of the handlebars, but they are angled in such a way that they can be seen from the side and back, said Caleb Lundberg, sales and product development associate of Cycle Force Group, a bike importer in Ames, Iowa.
Wireless turn signals are another idea beloved by riders who want to keep their hands close to the brakes, Mr. Lundberg said.
Bicygnals, a company with headquarters in the Britain, sells $70 front and rear wireless lights and turn signals in a sleek curved bracket that fits onto the handlebar. Buztronics sells a rear-facing arrow turn signal that fits just under the seat for $46. Both products are available online.
You can spend a few hundred dollars on a bike headlight alone these days. At just under $300, the Taz 1200 from Light and Motion in Monterey, Calif., is said to put out one-third more light than the average car headlight and is good for riding on roads and on dark trails.
But for the average street biker there are more affordable options.
Relatively new on the market is the Serfas Thunderbolt lighting system. The taillight and headlights, which can be bought separately, easily strap onto a bike and are rechargeable with a USB cord. They are bright enough to make you squint, are said to hold a charge for 9.5 hours and cost about $45.
Virtually all of today's LED headlights and taillights for bikes have static and multiple flashing modes activated with the push of a button. Add to that a blue flashing light from BikeBrightz Ltd. in Toledo, Ohio and the guy pedaling home after work in the dark could be mistaken for a squad car. Strap the light bar anywhere on your frame, and at $15 each, you can vary your color scheme. It also comes in "mean green," "rocket red," "powerful pink" and "mellow yellow."
Brake lights, once a distant dream, are now also possible because of smartphone and gaming technology.
One product gaining notice is the Helios handlebar, Mr. Lundberg said. The specialized handlebars connect to a smartphone app that measures speed to rear-facing lights at the handlebar ends. The rider can set the lights to change color, essentially making them brake indicators. They also have headlights and a turn signal.
But a built-in GPS does more than that. It can also track the bike's location if it is stolen, connect to Google Maps for driving directions and turn the headlight on automatically as its owner approaches.
Revolights is another Kickstarter bike project. Powered by rechargeable lithium-ion batteries, the lights fit onto the bike's front and rear wheels and can be seen from the front and sides as solid circles of light while in motion, and blinking at rest. They cost $139 for each wheel or $229 for the pair.
And then there are the lasers.
The Xfire Lighting System projects two red beams onto the street on either side of a cyclist. The idea is to create the illusion of a bike lane where none exists, and to let drivers know how much space they need to leave when passing, said its maker, Alex Choi, of Los Angeles. The Xfire sells for about $30 and has a USB rechargeable battery.
In England, Emily Brooke is bringing her Blaze Bike Light to customers in September. The Blaze projects a green image of a bike rider in front of the cyclist, making it possible for nighttime drivers to see the glowing image even if the rider is in a blind spot. A price has not yet been set.
And speaking of glowing green lights, Pure Fix Cycles out of Burbank, Calif., has a different solution to the nighttime visibility problem. Zach Schau, a co-founder, has developed bikes with entire frames or wheels painted to glow a neon-greenish color at night if they have been exposed to at least an hour of bright sunlight thanks to a special phosphorescent paint.
The single-speed and customizable fixed-gear bikes, which cost $325 and up, do have drawbacks, though. They don't shine as brightly in low light as they do in total darkness. Their glow fades in time. And, of course, they are no substitute for the front and rear lights that are required for night riding in some cities, he said.
Still, there's the coolness factor. The eerie glowing frames are sure to get a second look from drivers, he said. "The brighter you are," Mr. Schau added, "the more visible you are."interact
This article originally appeared in The New York Times.