[SS-Traveller]

Originally Posted by .anshuman

Another 10 or 20kph and they would have booked you for dangerous driving...

I was intentionally at 60 (okay, 1 km more than 60) because I knew the speed limit is 60. No way was I going to exceed that limit by 10-20 kmph.

Originally Posted by GTO

Well, technically, you were still over the limit...even if it's by only 1 km/h .

I have no issue with being fined for doing 61 in a 60 zone, if that is what the traffic police want to follow consistently across the city. Unfortunately, they don't. In a 50 zone, their leeway is till 60. The issue is of declaring it as a 50 kmph zone when the published limit is 60. The challan clearly states *permissible speed limit 50 KM kmph. Actual speed of the vechile 61 KM kmph* (sic).

Originally Posted by tsk1979

Considering most speed guns have 5-10% error, this needs to go to court. This is plain revenue generation

It IS plain revenue generation, but I really don't have the time or energy to go to court over this.

Originally Posted by phamilyman

... True story!

I once had my 70 something speed get challaned as 87 kph because I refused to pay the enhanced challan and argued that it had not yet been hiked (i had documentation that it was 100 and not 400).

I indulged in no arguments with the personnel. I have video footage where they have said that the limit is 50. I am fine with that - but DTP says on their own website as well as on street notifications on the same road, that the limit is 60.

[SPIKE ARRESTOR]

A pure case of stubbornness (mera kaha pathar ki lakeer syndrome).

God knows if they calibrate / control their equipments. Just curious, have you cross checked the speedo error of your Scorpio?

Challaning officer should be sent to R-Three lessons in Delhi.

Prost
Spike

[SS-Traveller]

Originally Posted by SPIKE ARRESTOR

Just curious, have you cross checked the speedo error of your Scorpio?

The Scorpio reads 64 kmph at a GPS-indicated 60 kmph. This was the Swift, it reads 62 kmph at a GPS-indicated 60.

[SPIKE ARRESTOR]

Thanks, so that pretty much sums up the mysterious case of challans in Delhi. When will these guys improve.

Prost
Spike

[phamilyman]

Originally Posted by amitoj

What do they use? RADAR or LIDAR? Isn't LIDAR less error prone?



You meant 100, right?

So the thing was - challans were increased from 400 to 900 (mistake in orig post, sorry) but hadnt been implemented yet. My own colleague had gotten his similar challan reduced from 400 to 100 at the court maybe because the judge was in a good mood. I flatly refused to pay the 900 (he was asking for 700 bribe) because I had a xerox of his court receipt.

When I went to court, I was able to reconfirm that the challan was still 400, but that my offence was actually dangerous driving (>80 kph in a 60 limit zone) which entailed 1100 challan.

So much for arguing with policemen.

[drmohitg]

Off late I have ceased to witness these interceptors on the ring road near the Azadpur-Dhaula kuan stretch. Earlier it used to be a regular at the Rajouri Garden flyover. Have they returned? Where was this exactly SS-Traveller?

[SS-Traveller]

Originally Posted by drmohitg

Where was this exactly SS-Traveller?

Opposite Subhash Place, on the south-bound (from Azadpur towards Naraina) carriageway.

[DriverR]

Originally Posted by amitoj

What do they use? RADAR or LIDAR? Isn't LIDAR less error prone?

Speed guns use RADAR technology. Yes, LIDAR is more accurate, but is typically used for scanning/3D imaging purposes.

[tsk1979]

Originally Posted by DriverR

Speed guns use RADAR technology. Yes, LIDAR is more accurate, but is typically used for scanning/3D imaging purposes.

No, speed guns can use LIDAR or RADAR. Not sure about India, but in USA many cities(esp well funded ones) have moved to LIDAR.
This is mostly to beat radar detectors. LIDAR can be detected, but by the time you detect it, you are too late

[GTO]

I'm surprised at some of the replies and how we've come to naturally expect a 'bit of concession'...like it's our birth right.

Why should we take a '5 - 10%' grace for granted? Does the law say that? Nope, it's black & white.

Sorry, if the speed limit is 60, that's it. It's 60....a fixed number, the board doesn't read '60ish'. If you're over 60, you're going to be fined. Just like if your car registration says seating capacity of 7, it means 7. Don't complain if you got an 8th onboard and got fined. Or if you got to the departure gates just '3 minutes' after you were told they'll close at, and missed your flight.

I understand SS-Travellers point that the speed limit has been incorrectly stated on the challan, but the fact is, he was indeed over even the real speed limit. Getting a discussion on 'targets' and all is irrelevant to this discussion as the speed limit was exceeded.

I applaud the cops who enforce speed limits so strictly.

[tsk1979]

Originally Posted by GTO

I'm surprised at some of the replies and how we've come to naturally expect a 'bit of concession'...like it's our birth right.

Why should we take a '5 - 10%' grace for granted? Does the law say that? Nope, it's black & white.

How can it be black or white when the manufacturer stated accuracy of a device is 5% when caliberated.
Lets say you are doing 59kmph.
Due to 5% error, it can show you as 61kmph. Should you still be fined?

Sorry, if the speed limit is 60, that's it. It's 60....a fixed number, the board doesn't read '60ish'. If you're over 60, you're going to be fined. Just like if your car registration says seating capacity of 7, it means 7. Don't complain if you got an 8th onboard and got fined. Or if you got to the departure gates just '3 minutes' after you were told they'll close at, and missed your flight.

Wrong analogy. 7 people in a car means 7 people. It is not possible to have 7.2 people(unless you are carrying bodyparts, in which case, its a whole new can of worms)

I understand SS-Travellers point that the speed limit has been incorrectly stated on the challan, but the fact is, he was indeed over even the real speed limit. Getting a discussion on 'targets' and all is irrelevant to this discussion as the speed limit was exceeded.

I applaud the cops who enforce speed limits so strictly.

Again, where you can accurately measure limit, you can set a hard limit. When you have a device incapable of accurate measurement, how can you set a hard limit. This is the reason, in USA if you get a ticket within 5% of speed limit, the ticket will be thrown out in court.
Its not expecting leeway. Its accounting for measuring error.

[Kaumad]

Originally Posted by tsk1979

How can it be black or white when the manufacturer stated accuracy of a device is 5% when caliberated.
Lets say you are doing 59kmph.
Due to 5% error, it can show you as 61kmph. Should you still be fined?

Again, where you can accurately measure limit, you can set a hard limit. When you have a device incapable of accurate measurement, how can you set a hard limit. This is the reason, in USA if you get a ticket within 5% of speed limit, the ticket will be thrown out in court.
Its not expecting leeway. Its accounting for measuring error.

I am sorry TSK but I am in complete agreement with what GTO said.

When you very well know that measuring equipment has an inherent inaccuracy, you could have factored that in and reduced your speed accordingly. This way, even if the cops had an instrument with the worst reading, you would still be within the limit.

Why did you not do that? Would have been a simpler thing to do than argue about equipment inaccuracy, isnt it?

Whenever there is a speed limit in the city road, I always drive about 10 kmph under it, simply because of my reasoning above. I am eliminating the consequence of inaccurate measurement right there!!

[GTO]

Originally Posted by tsk1979

How can it be black or white when the manufacturer stated accuracy of a device is 5% when caliberated.
Lets say you are doing 59kmph.
Due to 5% error, it can show you as 61kmph. Should you still be fined?

Sorry, I find it hard to believe every speed gun out there is out of calibration. Also, lets not forget that you're saying the accuracy is 5%. That means, the probability of it understating is as much as it overstating.

Don't also forget, the probability of a speed gun being overoptimistic is as much as your car's speedometer.

7 people in a car means 7 people. It is not possible to have 7.2 people(unless you are carrying bodyparts, in which case, its a whole new can of worms)

I think you're getting what I'm saying here. With the masses, it should be black & white....an absolute number. No grey area (oh, we'll allow or expect 5 - 10%). Why?

Similar to our 2 smiley / post rule. No matter how long the post, and even if some posts are super long, 2 smileys means two (not "we'll allow 5 smileys if the post is long).

This is the reason, in USA if you get a ticket within 5% of speed limit, the ticket will be thrown out in court.

Says who? I know students who got fined for doing 32 mph in a 30 zone (i.e. my college neighbourhood). Students being students will always contest the ticket, but they've badly lost.

[tsk1979]

Originally Posted by GTO

Sorry, I find it hard to believe every speed gun out there is out of calibration. Also, lets not forget that you're saying the accuracy is 5%. That means, the probability of it understating is as much as it overstating.

Don't also forget, the probability of a speed gun being overoptimistic is as much as your car's speedometer. .

Speedometers are designed to overstate the speed. So in any car, if you are at 100, if you take a GPS you will see speed between 95-98kmph on the GPS.
However, when it comes to devices such as RADAR guns(LIDAR is 2% inaccuracy), it can report +/- 5% randomly. This is due to the nature of the way RADAR works.

Modern calibrated radars have higher accuracy. Its usually +/- 1.5mph which is approx 2kmph.

But before each shift the RADAR must be calibrated. I seriously doubt this happens in India.
The reason I say this is that I was stopped for 95 in 90 zone when the GPS was continuously indicating 88kmph(I knew there are always cops there so I was driving at 87-88kmph, keeping 2kmph margin.

I had to pay 400rs to the Haryana cops.
If Delhi police is using LIDAR, then its +/-1kmph, so 1kmph below the limit will save you. Lets assume Delhi uses the highly accurate LIDAR.

That said, the challan said 50kmph. Now it means, if he had been doing 59kmph on the radar gun, he would still have been challaned, inspite of DTP website and posted limit being 60.

EDIT: I found out that newer RADAR guns have an accuracy of +/- 1mph when calibrated. Older models were +/-3mph

[amitoj]

Originally Posted by GTO

Says who? I know students who got fined for doing 32 mph in a 30 zone (i.e. my college neighbourhood). Students being students will always contest the ticket, but they've badly lost.

Possible that they were in the Zero Tolerance zone.
Otherwise, it is quite common here to contest your ticket and get it reduced to a smaller fine, or even just a warning.
I read this nice article on what to do when pulled over, that will reduce your chances of getting a ticket
http://oppositelock.jalopnik.com/how...aff-1645604557