Vehicle: Car: Speed: Limit: Notice
Current Speed Limit Indicator   (+31, -1)  [vote for, against]
Device displays current speed limit.

I'd like a device that reads the signs for me, displaying the current speed limit and any other current conditions.

It is a nuisance driving on roads that go through small towns. The speed limits go up and down constantly. Miss one sign and run the risk of an accidental speeding ticket. Selma, Texas used to get the majority of its tax revenue from a notorious speed trap based on a lowered speed limit until the state government stepped in.

Road signs use a very consistent font, outline, and color scheme (within a region) so it shouldn't be too hard to use OCR to scan for them.

I'd also like for it to give an audible indication of a red or green light. This would allow me to sleep or read maps at red lights.

This is much like the relative speed indicator, but I want absolute speed.
-- tolly2, Feb 05 2002

Speed Limit Sensors http://www.halfbake...d_20Limit_20Sensors
With new speed limit sign technology, probably more realistic than computer vision. [jutta, Feb 05 2002]

Siemens: electronic traffic sign recognition http://www.siemensv...V-200608-005-en.htm
Looks like I have to eat my words - here it is! [jutta, Oct 16 2006]

35
-- thumbwax, Feb 05 2002


thumbwax: hasn't anyone told you that it's dangerous to drive and surf at the same time.
-- st3f, Feb 05 2002


How about - radio device in sign sends signal to car. Car chip limits revs. I've seen a trial of this in california. No one breaks limit, everyone safe - but a bit prescriptive.
From my point of view as parent though, would love this bit to work so that you could enforce a low speed limit near schools and school crossing points. On the grounds that it could lead to this, I'll give you a croissant.
-- goff, Feb 05 2002


I watched my grandmother, at age 62, get her first speeding ticket ever. It also was in a small town where there were these "speed traps" of suddenly lowered limits. It was also the first time I ever heard her cuss. Croissant!
-- dana_renay, Feb 05 2002


Dare I mention GPS? Surely this is only a matter of time.
-- pottedstu, Feb 05 2002


This doesn't work, because the important bit is not "is it 65 or 35?", it's "how strongly does the local community enforce the rules?" And that, unfortunately, isn't written on the speed limit signs.
-- jutta, Feb 05 2002


[jutta] Granted you don't know what the risk is, but you'd know you're taking one.
-- phoenix, Feb 05 2002


I concur with pottedstu. GPS systems have the speed class information. It is only a matter of time before they are implemented.
-- concept, Jun 10 2003


[tolly2] I've also had a similar complaint and solution bouncing about in my mind. Building upon your post and [goff's] annotation...Transponders on speed limit signs that would send a signal to a receiver in the car. The receiver would then display the current speed limit and other information such as whether you are in a school zone or work zone. When an accident occurs on a road, the patrolman could toss out a transponder that would tell traffice to slow down, etc.
-- Salted Nuts, Jun 07 2004


Although I'm too lazy to look for more information on the Web, I know (i.e. seen on TV) that at least one company (IIRC BMW) has already developped such a system. It displays symbols of recognized signs (not only speed limits) in the speedometer area. For scanned speed limits it would IMO make sense to highlight that number or marker in the tachometer itself, or colour the acceptable range green.

Of course it would be a lot easier if all countries used the same unit for speed limits (km/h) and similar signs (round, black numbers, white or yellow background, red border). In Europe that excludes only the UK, AFAIK.

This OCR approach is of course just one way of doing it, but I don't see all authorities in the world investing a lot of money into upgrading all their traffic signs with radio transmitters, because, after all, if you don't pay attention to signs, you shouldn't be driving a car in the first place. Even if they did, cars would still have to get a receiver that probably isn't much cheaper than said OCR device. OTOH it is harder to miss a radio transmission than to digitally overlook a sign.

To conclude, I expect such a driver aid to appear in upper class limousines very soon (2005-2007).
-- Crissov, Feb 19 2005


Paint barcodes on the road. Aim a laser down under the bumper. Use a standard calibration strip so the car's computer can compensate for changing read speed; alternately tie it to the spedometer to do this. Paint the stripe in line with speed limit signs.

Should be relatively cheap to implement this way.
-- Chrontius, Feb 20 2005


Barcodes could work, but they could also be easily obscured by vandals. I like the transponder idea, as it would (as suggested by [salted nuts]) allow quick and easy local modification as necessary by road maintenance and law enforcement personnel.

As for display, a "bug" on the speedometer would be simple, obvious, and unobtrusive. Maybe have it change color. Green when you're well below the speed limit, yellow when you're within 5 mph below, red when you're at or exceeding by 5 mph, flashing red/yellow when you're exceeding by more than 5 mph.
-- Freefall, Feb 22 2005


I propose to use passive RFID transponders buried under the asphalt on each lane. So each vehicle receives only its indication adressed for that specific lane. No maintenance ever, vandal free, no wires, no batteries. It will work for ever as long cars do not fly. Simply. GPS can not work, you can not guarantee having everyone updated his/her speed limits digital mapping.
-- inventcat, Mar 28 2006


I like it. Instead of staring around bushes and trees to try and spot the speed limits, I can keep my eyes on the car ahead of me, and my speedometer.
-- ye_river_xiv, Jul 13 2006


Aw hell, this is all too complicated. Let's all go back to the good ol' days of horse and carriage. Enjoy the scenery for once, and look at the signs for once.

I feel I've said this before... odd.
-- NotTheSharpestSpoon, Jul 14 2006


It could be possible to tie this in to both a GPS (which could get its speed-limit data from a database, as well as trying to read signs or barcodes or transponders) and the cruise-control of your car, subject to driver acceptance of the speed change:

"The speed limit has increased to 75 miles per hour. Press the 'Yes' button on the navigation screen to set the cruise control speed to 75 miles per hour."
-- land, Oct 17 2006


Speeding tickets are not accidental.....They are obtained or given intentionally. Personally I like to obtain mine....
-- Chefboyrbored, Oct 18 2006


Maybe GPS systems could indicate if you are approaching a notorious speed trap.

I think AAA keeps track of speed traps.
-- talldave, Feb 01 2008


//I think AAA keeps track of speed traps.//
I understand that if an AA man didn't salute you, it was a warning that there was a speed trap ahead.
(Note to US readers: AA does not stand for Alcoholics Anonymous)
-- AbsintheWithoutLeave, Feb 01 2008


[AWL]: That's true; members were told that a patrol should always salute, and if one didn't, the member should stop and ask why. The reason was generally that there was a police speed trap ahead, but the official excuse was that he hadn't noticed the member's badge. As the badge was around eight inches tall and bright yellow, this was a pretty thin excuse.
-- angel, Feb 02 2008



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