Here's an idea. Why not design brake lights whose intensity varies depending up on how hard the driver is stomping on the pedal?

It might help ease some of the overreaction I've seen on various highways and interstates in the last few years.

According to a quick search, this isn't a new idea. But why it it only mentioned on the expensive 5 series BMW cars?

Posted by jzawodn at August 10, 2004 08:38 PM

Reader Comments
# Derek said:

I think you and I talked about this at the MySQL Users' Conference. What I said I wanted was a series of lights, and the harder the pedal was depressed, the more lights would light up off the centerline.

That's how I would design it, anyway.

on August 10, 2004 09:00 PM
# Jeff Boulter said:

Yeah, and when you were idling they would oscillate like a cylon. Cooool.

on August 10, 2004 09:23 PM
# Geof said:

Derek's idea is a better one, honestly. People will see more light more clearly than they will a greater intensity of light. [That's the premise of the third brake light being above the centerline of the vehicle.] You would also have the additional design problem of how to deal with running lights; most cars currently light the brake lights at a low intensity when the headlights are engaged. Folks that drive with their heads on all the time---like myself---will foil such systems.

Also, brake pedal pressure varies as the brakes wear down. Flooring new brakes is a bit different than flooring worn-out brakes. :(

on August 10, 2004 09:23 PM
# Daniel Farinha said:

That's an interesting idea.
A related idea would be for the car, when going at high speed (say in a motorway) and when you need to break hard, to switch on the hazard lights automatically.

It would be really useful in my car, as the hazard lights button is small and hidden away in the dashboard. Not a good thing having to look away from the road to find it and press it, during an emergency stop.

Just last week I saw a car behind me swerve as he he didn't realise we'd all stopped suddenly in a queue until quite late. He eventually managed to stop, and I was still trying to find the darn button.

on August 10, 2004 09:55 PM
# jr said:

The first I heard of an idea like this it actually used strobing. The harder the car was stopping the faster the strobe. The reason for strobe over intensity is because our vision is wired for changes. We tend to notice things flickering or blinking more so than things that aren't.

I'd also note that these approaches are usually only successful while they're novel. It's one of the reasons that third lights are already proving to be less useful than they thought they'd be, since folks are starting to ignore them. I like them because you've now reduced the likelyhood of some moron having all three brakelights out is less.

I've seen a number of motorcycles take this tactic for their headlights and brakelights.

on August 10, 2004 10:19 PM
# Alex said:

I was coming up on some stopped traffic on the freeway (I think on 101 near 85) at a relatively high speed and the car in front of me got my attention by stepping on and off their brake to flash the brake lights at me. I've done it in similar situations ever since.

on August 10, 2004 10:30 PM
# Ferg said:

I wish there was some kind of warning light that would indicate that the driver ahead of you is elderly, distracted or an idiot. Buicks, of course, make elderly drivers easier to spot via their perpetually blinking turn signal (sfaik, the only option is to change which side blinks).

Some kind of indicator that drivers are distracted by their cellphones would help too. Perhaps a head-up display indicating nearby sources of GSM, CDMA, or god-forbid TDMA. I'm sure Lockheed Martin Missiles and Space have something that could be tweaked for this purpose.

on August 10, 2004 11:09 PM
# Mark said:

I hate people who drive with their headlights on during the day. Fucking why? Safety? Not! They make me switch my rear-view mirror to night mode, thereby making it much harder to see them and everybody else. Or, I can leave it in day mode and be more likely to be involved in a crash because I'm blinded by their lights. Cars should have devices which prevent headlights from functioning above a certain ambient light level.

I also hate bikers with INCREDIBLY LOUD FREAKING PIPES! They don't save lives - they make the biker much more likely to suffer the wrath of everybody else within a half-mile radius whose eardrums have just been blasted. But that's another rant...

on August 10, 2004 11:34 PM
# Sumeet said:

That's a very neat idea. Easy to implement as well. This adds to Derek's idea above:

The brake lights can be divided into two-three sections, and depending upon the displacement of the brake pedal, the corresponding number of sections light up.

If I brake really hard, all the three sections lite up. But then, we must have a standard size of brake lights for most cars, and that would restrict design. :)

on August 11, 2004 12:09 AM
# tfr said:

On Daniel Farinha's idea: this is also already done on a bunch of newer BMWs, Mercedeses and such. I've seen them go off multiple times in the vicinity of me, and not yet in the "brake for your life" situations.

On driving with headlights on - it's required by law here, and AFAIK, in a majority of the European countries. And having grown used to it, it's the one thing that bothers me most driving in the U.S. - people just don't bother to turn on their headlights until it's so pitch black they can't see anything anymore. The headlights aren't just so you could see what's ahead while you're driving. They're also useful so the people coming from the opposite direction could notice you earlier.

Mark - if someone's tailgating you and their low beams are blinding you in the day time through your rearview mirror, then something must be wrong either with the mirror or your eyes. Do you feel a burning sensation when they turn on the blinkers?

on August 11, 2004 12:50 AM
# Tristan said:

Following up on Daniel's idea of the hazard lights switching on when you break hard, quite a few modern european cars do it already.

As TFR mentioned it, it's probably standard on BMWs and Mercs, but I've also seen it happening with a Peugeot 406 and a Renault Laguna, in both cases on fairly new rental cars, but hardly top of the range cars.

I believe it's linked to the speed you're driving at and the amount of pressure you put on the brakes.

The first time it happened to me was on a german motorway doing a good 180km/h when a truck pulled on the fast lane in front of me. If anyone had been following me, I'm sure they'd have appreciated the early warning since it would have taken me a good second or so to hit the switch the hazard lights. And I'm not even sure I would have thought of doing it, as scrambling for the hazard lights is not the first thing that comes to mind in that situation.

While on the subject of having a car using its lights to automatically communicate with the other drivers, what would you guys think of a system where your car signals (soft pulsating light maybe) that the car behind you is way too close for the speed both cars are travelling at?

If more cars get fitted with parking assistants (system that beeps when you're reversing a bit too close to something), I'm sure the system could fairly easily made to measure the distance at which the next car is.

on August 11, 2004 03:36 AM
# Taz Lake said:

Interesting discussion going on here. Check out the discussion of this idea which I presented over at (which happens to be the most popular topic):

It actually wasn't novel when I presented it, but you may find the discussion there interesting, as well.

on August 11, 2004 08:11 AM
# shc said:

i believe these are standard on the new bmw m3s

on January 24, 2005 08:38 PM
# Rod Pieper said:

Unfortunately you may run into issue with the state safety inspection. VA does not allow any pulsating/blinking in brake lights.

on May 12, 2005 03:11 PM
# syed naqvi said:

which company manufactures variable intensity brake lights and where can a person purchase one ?

on May 17, 2005 10:39 PM
# Michael said:

About 30 years ago I read an article about a pulsing brake light system installed on San Francisco taxicabs that lowered rear end collisions. The pulse rate varied in proportion to the amount of braking provided. Electric brakes hooked up to a trailer being towed use this principle, probably a rheostat of some sort to vary output. I cannot locate a unit designed like this. Anyone who can help me on this?

on August 23, 2005 06:18 AM
# NRG said:

Why doesn't anyone design an electric circuit to do this? I have already tweaked my 3rd brake light with 3 LED units, instead of one bulb. hmmm. great idea.

on May 2, 2006 11:04 AM
# Phoenix Bueller said:

Around Phoenix, the Muni busses have brake light strobes that speed up as the driver increases brake pressure. Obviously the key to this is some technology to translate the varying brake pressure to a varying analog voltage. I'm looking for this. The plugs to make it drop-in would be an issue, but I'd like to kit up the pressure sensor with a bit of circuitry to flash an LED, maybe I could sell a few on eBay. Maybe I'll make variable brightness an option, for those who dislike flashing lights.

on May 30, 2006 10:42 PM
# Mr. Roman Larin said:

Iīm afraid that the idea of a variable brake light indication ( linear ) has allready been developed and pattented in the country of Belgium. Well itīs a great idea anyway.

Ps. Mark, I donīt understand the headlights during daytime allso, but for example Volvo is producing cars where you can NEVER turn the headlights off. Ps for gadgets itīs better to look at Citroen ( Shitty car, but cool gadgets ) and of course the Mercedes S-Class :)

on July 10, 2006 01:09 AM
# Tina said:

Regarding your comments on brake lights being designed to give the driver in front of you more information, my husband has invented one which has just been launched on th market called a VBI (vehicle braking indicator)(patent pending) which can fit easily to any vehicle, unlike the BMW 5 series which apparantly glows brighter and it is only on new cars!! The VBI has a bank of 30 led's and lights progresively, the harder you brake the more banks of led's light, then if you emergency brake the light bar will flash to warn the other drivers how hard you are braking and fits any car, old or new and works on the inertia of the vehicle, not through the brake system. What do you all think?

on October 26, 2006 03:21 PM
# Brian said:

Tina - I'd love to hear more about your husband's background and how he came up with the idea. Shoot me an email.

on October 26, 2006 08:54 PM
# Tina said:

Brian with ref to your comment regarding the VBI (My husband brake oight invention) have a look om his web site or just type in VEHICLE BRAKING INDICATOR it will give you a bit more info etc, the VBI is now PATENT GRANTED not pending.

on December 21, 2006 03:03 PM
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