Speed limit tolerances

[agentsteel53]

State law sets the "start point" at 12 over the limit in work zones.

that, frankly, is utterly fucking stupid.

speed limits should not be a guessing game.  if you're going to have them, enforce them.  if you're going to enforce them, enforce them consistently.  otherwise just take down the big white signs with big black numbers and tell the world "you, you poor puppets, have no idea how fast you're allowed to go" because that's how it really is.

[vdeane]

With that policy, if you keep the needle on the speed limit, you probably don't even have to slow down in work zones!  They could simply set up a zero-tolerance policy for speeding (ticket for even 2 over the limit) and accomplish the same goal.

[Scott5114]

With that policy, if you keep the needle on the speed limit, you probably don't even have to slow down in work zones!  They could simply set up a zero-tolerance policy for speeding (ticket for even 2 over the limit) and accomplish the same goal.

Except you cannot do that, because speedometers probably have a normal margin of error of at least ±2 mph.

[froggie]

That's specifically for the work-zone/school-zone cameras.  There's nothing stopping the Maryland cops from pulling you over for going less than that amount, though based on personal observation, they tend to wait for the speedsters that are flying down the road at 80-90+.

[agentsteel53]

Except you cannot do that, because speedometers probably have a normal margin of error of at least ±2 mph.

there's a wide world of sports difference between 2 and 12.

[vdeane]

Except you cannot do that, because speedometers probably have a normal margin of error of at least ±2 mph.

Which you can figure out with GPS and any signs that report your speed to you (I happen to know that my speedometer reports itself as 3mph faster than my car is actually going due to a couple of signs on a local road that say "Speed Limit 35; Your Speed XX").  I don't believe digital speedometers have this margin of error.  My Mom's car has one and it is EXACTLY right.

[Brandon]

Except you cannot do that, because speedometers probably have a normal margin of error of at least ±2 mph.

Which you can figure out with GPS and any signs that report your speed to you (I happen to know that my speedometer reports itself as 3mph faster than my car is actually going due to a couple of signs on a local road that say "Speed Limit 35; Your Speed XX").  I don't believe digital speedometers have this margin of error.  My Mom's car has one and it is EXACTLY right.

Radar from those signs not perfect, and can vary by quite a bit.  They usually show one as going slower than he/she is.  In addition, speedometers are only good to +/- 5%, including digital speedometers.  Odds are, the radar on those signs has not been calibrated recently.  Even cops fail to calibrate their instruments on a regular basis (this can trip them up - ask for calibration records in court).  GPS isn't perfect either.

[Scott5114]

Sure, but who the hell is going to actually find the variance in their speedometer and obsess over it constantly? If you get so draconian to write a ticket for 1 to 2 miles over the speed limit, such that people actually trying in good faith to follow the law get screwed over, there will be hell to pay for the county sheriff.

[agentsteel53]

Sure, but who the hell is going to actually find the variance in their speedometer and obsess over it constantly? If you get so draconian to write a ticket for 1 to 2 miles over the speed limit, such that people actually trying in good faith to follow the law get screwed over, there will be hell to pay for the county sheriff.

unless you're in some podunk southern town where you re-elect Cousin Ed every year.

[Bickendan]

Or New Rome...

[Scott5114]

NEW ROME DOESN'T EXIST.

[Brandon]

NEW ROME DOESN'T EXIST.

Not anymore. 
They got unincorporated!

[vdeane]

Radar from those signs not perfect, and can vary by quite a bit.  They usually show one as going slower than he/she is.  In addition, speedometers are only good to +/- 5%, including digital speedometers.  Odds are, the radar on those signs has not been calibrated recently.  Even cops fail to calibrate their instruments on a regular basis (this can trip them up - ask for calibration records in court).  GPS isn't perfect either.

Or ever.  Those signs have been reporting the same way since they were installed 2-3 years ago.  Don't they use the same radar the police use?

[deathtopumpkins]

If those signs use the same radar as police do, I'm scared. Drove by quite a few on Monday and only two were within a few mph of my speedometer's speed. One was 22 mph off.

[mightyace]

Those signs as well as the ones on portable VMSs Pennsylvania often use radar units that have become obsolete for police use.

[InterstateNG]

Those signs as well as the ones on portable VMSs Pennsylvania often use radar units that have become obsolete for police use.

They just put one of these in my neighborhood on Monday.  Walking by it, it clocked my speed at 7-10 mph.

[Truvelo]

I wish we had a 12mph tolerance. Instead it's 10%+2mph so in a 30 the trigger speed is 35, 40 is 46, 50 is 57 and so on. On an open freeway where the limit is 70 the mobile Talivans that sit on bridges are nabbing people for doing 79 in perfect safety

[Scott5114]

9 mph is a pretty decent-sized tolerance, though. I've always heard around here that the tolerance is generally 5 MPH.

[Brandon]

9 mph is a pretty decent-sized tolerance, though. I've always heard around here that the tolerance is generally 5 MPH.

Tolerances seem to vary from place to place, and even from vehicle to vehicle.  I've gone past cops on the expressways and tollways here at 10 over and never been bothered.  But, then again, I follow at 2 seconds or more distance, don't drive like a douche, and keep my cell phone out of sight while driving with the flow of traffic.  On the other hand, I don't really speed much on surface streets either, just the expressway.

[Scott5114]

Shall I completely ruin the point of this thread by bringing up relativistic effects?

[agentsteel53]

Shall I completely ruin the point of this thread by bringing up relativistic effects?

just do it last week or something.

[Scott5114]

Oh, man are we going to get into weird time shit too? Predestination paradoxes are DELICIOUS.

[agentsteel53]

Oh, man are we going to get into weird time shit too? Predestination paradoxes are DELICIOUS.

we were, but then we won't be.  except for when we will, at which point we will have done so.

[RoadWarrior56]

Do they still have the NO TOLERANCE auxiliary signs in Oklahoma below the speed limit signs?  When I worked there in '85, they were all over the place.

[Scott5114]

Not on freeways. They might still be posted sporadically on turnpikes, which have a higher speed limit.