High mount brake light flasher

LiteIsRite · Postby **LiteIsRite** » Sat Jul 09, 2016 3:22 pm

Always on the lookout for ways to make the car more visible to other motorists, I read something in a thread on the big forum that started me thinking about having the 'high mount' (the term 'high' is a bit ambitious on an MX5, right?) / centre mount brake light flash when the brakes are first applied.

After a bit of looking around, I settled on this electronics module http://tinyurl.com/gwanp8y and one of these LED bulbs http://tinyurl.com/jun9rhm

This is how it looks on the car:

and1 · Postby **and1** » Sat Jul 09, 2016 5:31 pm

I gutted the housing and replaced it with a board full of an array of flat superflux red LEDs. Much brighter than the standard bulbs. I think in total i used 36 in a 3x12 array. I also used a 9V voltage regulator to bring it down to a more stable and usable state and 100 ohm resistor before each of the 12 columns. A flashing setup could easily incorporated into this setup if need be.

LiteIsRite · Postby **LiteIsRite** » Sat Jul 09, 2016 9:05 pm

Sounds great! Any pics or video? Had a look in your garage thread but couldn't see it. Nice build, by the way... :mrgreen:

(green with envy)

davekmoore · Postby **davekmoore** » Sat Jul 09, 2016 11:25 pm

Don't get me wrong, I think it could be a good idea, same as a brighter light the hard you brake could also be a good idea. But is it legal?

bruce · Postby **bruce** » Sun Jul 10, 2016 1:38 pm

Would a flashing red light make you stop quicker? I don't think so as we are accustomed to a solid red light. It may cause confusion.

LiteIsRite · Postby **LiteIsRite** » Sun Jul 10, 2016 4:46 pm

davekmoore wrote:But is it legal?

Good question - flashing red lights are only legal on emergency vehicles, but that's regularly flashing and usually much brighter than what's going on here, but I'm still taking a bit of a risk.

bruce wrote:Would a flashing red light make you stop quicker?

A number of studies have been done that suggest it may help get a faster response from following drivers. One example: http://tinyurl.com/hfbcdsj

Smacca · Postby **Smacca** » Sun Jul 10, 2016 8:41 pm

I was a big fan of the flashing centre brake light mod as an additional warning/safety feature. Especially if it's hyper-flashing to suggest the urgency of the deceleration.

However, recently I followed an 86 with this mod. After sitting behind the 86 in heavy traffic for only 5 minutes, the flashing LED brake light got very annoying very quickly! Enough to incite road rage from some drivers I'm sure.

I would have the flasher on a switch to turn on only during track days, club runs, spirited driving ect. New Mercs, Audis and BMW's have their brake lights flash when the ECU detects heavy or urgent braking (deactivated for ADR), but surely that would be tricky to retrofit.

LiteIsRite · Postby **LiteIsRite** » Sun Jul 10, 2016 10:36 pm

Smacca wrote:I was a big fan of the flashing centre brake light mod... However, recently I followed an 86 with this mod. After sitting behind the 86 in heavy traffic for only 5 minutes, the flashing LED brake light got very annoying very quickly! Enough to incite road rage from some drivers I'm sure... I would have the flasher on a switch to turn on only during track days, club runs, spirited driving ect.

Thanks, Smacca, I appreciate the feedback - I was wondering what extended exposure might be like for following drivers. The car is only a weekender, so doesn't often get tangled in stop-start traffic, but I'll look into a remote override switch to stop the flashing when it isn't appropriate. There are more sophisticated controllers out there that won't repeat the flash cycle if the brake is activated less than 15 seconds after the previous activation... more expensive but maybe the better solution.

davekmoore · Postby **davekmoore** » Mon Jul 11, 2016 2:47 pm

Smacca wrote:New Mercs, Audis and BMW's have their brake lights flash when the ECU detects heavy or urgent braking (deactivated for ADR), but surely that would be tricky to retrofit.

Now that, is a Good Idea, teamed with the existing (even on humble Mazdas) flashing of the hazard lights when a threshold is reached - think it's at emergency brake assist activation, which is around 90% of a full ABS intervention - happy to be corrected.

hks_kansei · Postby **hks_kansei** » Mon Jul 11, 2016 2:56 pm

Looking at the Video, if I was behind that car at night it would take me a moment to work out if it's actually braking, or if the high mount light is just shorting out.

Or, i'd think they're just lightly tapping the brakes to slow a little bit..... which kind of defeats the purpose of the flasher since it's supposed to warn drivers of a sudden/hard braking...

Daytime wouldn't be as much of an issue, since you'd be able to clearly see the main lamps, but at night, with the tails on, often the main brake lamps don't stand out as much as they really should.

Basically, if I saw this my first thought wouldn't be "sh*t, they're braking hard!" it would be "what are they doing, are they actually braking? is the light shorting?"

LiteIsRite · Postby **LiteIsRite** » Mon Jul 11, 2016 3:30 pm

hks_kansei wrote:Looking at the Video, if I was behind that car at night it would take me a moment to work out if it's actually braking, or if the high mount light is just shorting out.

Thanks, hks, for your perspective. I may shoot another video at night to see what the overall effect is. I tend to think that, as long as the output isn't too different between the outer brake lights and the centre one, the message to following drivers should be clear enough.

Based on smacca's feedback, I've also ordered a module with more advanced features - http://tinyurl.com/j9ywhu7 - to be kinder to other motorists , and see if there's another flashing pattern that's more effective. This module also has the power handling capacity to drive all the brake lights together, so that's another option I'll experiment with, but that may simply reinforce what you're suggesting - the flashing is interpreted as a fault rather than an application of brakes.

It's an interesting exercise in any case.

bruce · Postby **bruce** » Mon Jul 11, 2016 3:31 pm

My thoughts exactly. 'Why is this light repeatedly flashing?' By then I may already be inside your colon.

Mr Morlock · Postby **Mr Morlock** » Mon Jul 11, 2016 3:43 pm

It is totally illegal. Don't people interested in cars understand that lighting is regulated. Anyone been caught behind a driver with the rear fog lamp lit on a bright day and be peed off because it dazzles and annoys? Light outputs are regulated so they are not dazzling drivers. Numbskulls driving around with fog lamps lit on bright days is another example but the message fails to be heard or seen in the RACV or NRMA magazines etc. The centre mount stop lamp and the outboard stop lights are fully visible if the following driver is looking. The area to be seen on an MX5 is the front and fitment of legal DRLs is a good idea and now standard on ND and virtually all new cars.

LiteIsRite · Postby **LiteIsRite** » Mon Jul 11, 2016 4:30 pm

Yes, Mr. M, I agree totally with what you're saying about rear and front fog lamps, but that's different to what I'm investigating - and it is an investigation at this point, even if I didn't make that clear in my original post.

Mr Morlock wrote:The centre mount stop lamp and the outboard stop lights are fully visible if the following driver is looking.

Absolutely, and which tends to support the body of evidence collected so far in various studies, and already acted on in some countries, that the incidence of rear-end collisions is reduced in certain circumstances when a flashing light attracts the attention of a following driver - so that they are now 'looking' at the brake lights of the car in front of them.