Your bad driving encounters
- Thread starter Stu999
- Start date
You don't need to - unless the video speed and/or as is the case here on screen clock vs real time is completely out then over enough distance you can eliminate most variables in calculating the average speed - the longer the distance the less any small start and end point inaccuracy and exact clock tick matters. Even if you relax the distance and time elapsed to the max possible deviation it still comes back at over 74MPH.
I have no idea what is going on in respect to GPS speed here but given the reaction from the cops I'm leaning towards the actual speed being towards the upper end of my estimate for some reason.
You do realise that polices aren't always right, right? Countless videos and compilations showing exactly that where they get things wrong or are just out there to be power hungry or whatever policing the roads.
E* We already have some concrete facts of the matter without having to miscalculate numbers using a compressed and interpolated video.
1: No unsafe driving is on display other than from the actual police, the fact that they didn't stop me and the 3 series intervened seconds later indicates the X knew he did something inappropriate.
2: Satnav has not made any speed camera alerts which it only does if at an alert threshold.
3: It's a speed controlled zone so you have to be below any speeding threshold anyway.
E* We already have some concrete facts of the matter without having to miscalculate numbers using a compressed and interpolated video.
1: No unsafe driving is on display other than from the actual police, the fact that they didn't stop me and the 3 series intervened seconds later indicates the X knew he did something inappropriate.
2: Satnav has not made any speed camera alerts which it only does if at an alert threshold.
3: It's a speed controlled zone so you have to be below any speeding threshold anyway.
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If you were doing 73 on a GPS, you were speeding. Not only that it was wet conditions and no, that first police car did not cut you up. You got a mild warning by the cops and are trying to call them unprofessional. FFS take a step back and stop digging.
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I'm not accusing you of unsafe driving, additionally personally on the open road I don't particularly care what speed people do as long as it isn't excessively fast or excessively slow when it affects other road users.
Video compression and interpolation has little to no impact on the ability to calculate speed from a video when you have enough distance and a reasonably accurate clock to go by - there is enough in the video to fairly accurately place your speed above what you thought you were doing and almost certainly why the police acted like that.
AFAIK they use a 10% + 2 tolerance in that area so the top end of my estimate puts you on the border.
GPS speed isn't flawless - elevation changes or other conditions can affect it - I've even seen it overestimate my speed by nearly 10 MPH for several miles before when I've been cruising at 70 on the speedo - probably 68 actual.
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Yeah that only satisfies my own point that there was no unusual driving on display other than from the police X series. There is no reason at all to speed past then suddenly slow down cutting in front of me like that, that is unsafe and can cause accidents. That is the only things my video was posted to show. Nothing else is really relevant given everything was calm and safe up to that point.
GPS and in car speedo being that massively out (speedo would be showing 80ish based on your calculated speed) seems highly unlikely to the point of basically impossible unless MRK is racking up tickets in 30s daily.
The accuracy of a speedo often tightest at ~30 MPH, perfectly possible for it to be within 2MPH at 30 and 10 MPH out at 70, though usually over reads - but non-stock tyre/wheel sizes can result in it under reading.
The video and police reaction definitely err towards for whatever reason they were travelling faster than they thought - it isn't difficult to place the vehicle accurately enough over enough distance between 2 points and time elapsed using the on screen timestamps to reasonably calculate average speed, and in the non-sped up sections the clock progression is consistent with real time.
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The needle on the E46 never under reads regardless of wheels or tyres, it's always about on average 4-5MPH over what when at 75MPH GPS and I set cruise speeds based on what GPS shows not the needle. I know this because I've had multiple tyres and a set of loaner wheels on the car before so know what the variance can be. 73MPH GPS is well wiothin any under or over budget in GPS inaccuracy which can happen, it will never trigger any speed cameras as this variance is accounted for as well, again perfectly safe and legal. Going by a GPS indicated 70MPH cruise might actually be 73MPH actual too for example again because of variances in conditions.
This is also based on GPS from both car and phones so GPS is always showing the more reliable figure within the context of conditions outside obviously.
This is also based on GPS from both car and phones so GPS is always showing the more reliable figure within the context of conditions outside obviously.
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Video timestamps must be fair way out if you were definitely only doing 73mph GPS because measuring where you are at 03:17:23 (sign where the fence starts) to the gantry you pass under at 03:17:59, is 1300m and you cover the distance in 36s, which is 80mph average. Even if you were generous and added a full second either end, that'd still be 76mph average.
I would not base this on the video passing through any 2 points nor based on the timestamp, as said 'the cam records heavily compressed with interpolated frames nto make the whole motion look smoother/faster as that's what sells from the Chinese, the timestamp is just a reference point. It's not a dashcam for that kind of analysis, it is just to record an incident should it happen and provide that sort of visual aid.
It's highly amusing that a bunch of you guys are focusing on things that are not relevant when the actual issue originally on display is that a traffic cop car did a dangerous manoeuvre that /could/ otherwise cause an accident 
If the officer felt that i was being unsafe for the conditions then why not just flash the lights from behind and we pull over on the hard shoulder?
There is only really one question to ask here, why did the X speed past then suddenly cut me up which in the process blocked my view of the road partially with all that standing water spray and then what was effectively a brake check in adverse weather conditions.
If the officer felt that i was being unsafe for the conditions then why not just flash the lights from behind and we pull over on the hard shoulder?
There is only really one question to ask here, why did the X speed past then suddenly cut me up which in the process blocked my view of the road partially with all that standing water spray and then what was effectively a brake check in adverse weather conditions.
Maybe it’s because nobody saw anything dangerous from the police car.
Right at the start you moved across lanes, then cut across chevrons to as you claim “avoid a truck” but from what I saw the truck was able to stop.
You were speeding by your own admission, a cop car had to warn you to slow down. The cops did not cut you up from what I can see in that video.
Yet instead of holding your hands up and learning from it, you double down that you did nothing wrong and the cops were the bad drivers.
Right at the start you moved across lanes, then cut across chevrons to as you claim “avoid a truck” but from what I saw the truck was able to stop.
You were speeding by your own admission, a cop car had to warn you to slow down. The cops did not cut you up from what I can see in that video.
Yet instead of holding your hands up and learning from it, you double down that you did nothing wrong and the cops were the bad drivers.
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None of that really matters when you have a fair bit of distance and what seems to be a fairly accurate clock in the video to reference - in the non-sped up sections it is pretty much identical to the video time stats - I don't pretend to have an explanation but over the section they almost certainly clocked you the video makes it highly unlikely you were under 76 MPH and very likely doing something close to the 79.6 I calculated within about 3% accuracy. This isn't judged on perception of motion. Which is almost certainly why they decided to give you a warning, rather than pull you.
Again, such a subjective analysis is not relevant or even necessary/completely accurate, there is only one piece of unsafe driving on display and that is from the X series. Let's GIF that exact bit for reference as people seem to have just glossed right past this or have eyesight issues which worries me as to your awareness whilst driving on the road.
E* fixed words.
- Actual excessive speed
- Cuts in without indicating
- Brake checks down to HGV cruising speeds
- Is perfectly OK when I later overtake and continue on my journey and we part ways... Probably because the 3 series intervened telling X about what they did. Either that or they were doing some training exercise.
E* fixed words.
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