I was driving the other day and a sign on the roadside flashed that I was going at 25 MPH when my speedometer told me I was going at 30. How accurate are these signs?
2007-08-08 03:28:26 · 14 answers · asked by Helen F 2 in Cars & Transportation ➔ Safety
I passed one of the digital signs on the side of the road that displays your speed (not the one that just flashes up the spped limit on the road, the one that says what speed you are actually doing - this I know because the speed it showeed varied by a couple of MPH). It said i was 24-25 MPH, whilst my speedo said I was doing 30 MPH. Whis will be more accurate?
2007-08-08 03:48:49 · update #1
How do you know if your speedometer is accurate?
Try this ... when you pass some mile marker, capture the precise time to the second & what the mile marker number was. Try to drive at a steady speed (cruise control can help with that). Then do that again when passing another. Then do the math ... does it agree with speedometer?
Well are the mile markers in exactly the right places?
Do the same test several times on different highways.
You should find out if your speedometer is consistently high or low, and off enough to warrant getting a mechanic to fix it.
I can tell you that from my experience those signs are either within 2 mph of what my speedometer says, or there is confusion when there's a lot of traffic on the road ... am I seeing what it said about the car behind me, in front of me, to my side?
2007-08-08 05:05:34 · answer #1 · answered by Anonymous · 1⤊ 0⤋
They just put up a whole bunch of these in Chandler, Arizona. I was sitting at a light the other day and there was one of those signs about 500 feet up the road. With no moving traffic between the light I was stopped at and the sign (in either direction), the sign was displaying 31 mph. I don't think they are very accurate.
2007-08-08 11:30:17 · answer #2 · answered by Scott H 7 · 0⤊ 0⤋
If you are talking about the warning sign rather than the camera speed trap, I don't find the former to be very accurate.
I pass a couple every Sunday (going in both directions on the same 40 m.p.h.stretch).
Just for the sheer Hell of it (!) I try to catch them out - the one travelling West to East doesn't flash till I'm doing in excess of 40 mph, the other one East to West flashes up "40 mph Slow down" when you are doing 30!
The wonders of modern technology!
2007-08-08 10:42:40 · answer #3 · answered by Veronica Alicia 7 · 0⤊ 1⤋
hiya these signs are very accurate if you were doing 30 mph and the sign flashs it meant to warn you that you are doing over the speed limit , is this sign on a trailer well if yes that they flash at every car or wagon and tells them what speed they are doing and thats ment to just to remind you what speed you are doing anyways look on the bright side of it i can tell you for defo you wont get a ticket
2007-08-08 15:11:10 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Every speedo is infact 2-4% inacurrate
when your speedo shows you doing 33-34mph your infact doing 30mph
so when you go through a speed camera at 30mph your only truly doing 26-27mph.
2007-08-08 10:43:56 · answer #5 · answered by Red5 5 · 0⤊ 0⤋
If the tires on your vehicle are larger or smaller than the manufacturer recommendation, this could cause your odometer to give a false reading. You could be going slightly faster or slower than what you actually are driving. Improper tire size can also alter the actual mileage on your vehicle. I'm not an expert . . just makes sense to me.
2007-08-08 14:58:24 · answer #6 · answered by whyulookin4 3 · 1⤊ 0⤋
u mean a camera flashed you? if its a double flash , then thats more the issue.
if its say a dual carriage way, maybe it flashed the other car.. although my friend got a ticket and it was the car on the other side of the road that trigged it. So when he got the photo of the speeding, it showed that, and they dropped it.
some area's are 20's.. near schools..
they are accurate, maybe your speedo isn't.. (which is odd)
2007-08-08 10:35:08 · answer #7 · answered by junglejungle 7 · 0⤊ 2⤋
good old revenue collecters eh!! If you pass more than one or two of these and you get similar readings then trust your car. If you trust the roadside speedsign it will probably con you into going faster then you will get the good old bobby bonus to pay out to what will they think of next ????
2007-08-09 16:13:18 · answer #8 · answered by Anonymous · 0⤊ 0⤋
well surely the camera is more accurate as it would time you from one point to an other and work out your speed from that.
2007-08-08 10:36:59 · answer #9 · answered by mistahclarke 2 · 0⤊ 1⤋
thye are accurate. your speedo may be out of calibration.
mc.
2007-08-08 11:29:46 · answer #10 · answered by Michael M 7 · 1⤊ 0⤋