Hi Davos - great post !
I was caught by the auto-flagging algorithm about 2 years ago - I finished a ride but my fingers were too cold and wet to unlock my phone to stop the recording and when I started driving home I got a Strava alert within about a minute of me reaching 50 mph (I cropped the activity when I got home to resolve things).
Maybe I'm lucky, but in my area I rarely see obvious car rides - I maybe flag 2 or 3 per month (I've given up adding friendly comments on an Activity to highlight the issue as I never get a response). Perhaps there are quite a few keen local cyclists who between them help to keep things "clean".
I agree that the auto-flag algorithm should be tightened, such as taking account of gradient (not even pros can go up a long hill at 40 mph), and perhaps rider experience, such as someone who typically rides at 15 mph and then rides for an extended period at 30 mph.
I use to get notifications of people taking my KOM weekly to daily, at 100kmh from a freeway which near a MTB park. I raised it as a strava feature some years back, and it can be done simply done a number of ways, when riding cadence, power, heart rate & temperature(bike is now in car) these will be significant changes, checking the current KOM of segments that are being broken to standard deviation of the top times
This is flagging a dead horse. Strava claimed years ago to auto-flag, but here we are with 2 second, 300+ mile an hour KOMs. Strava IS a data company, which makes its inaction bizarre.
Just bumping this because it's still an obvious problem. It's getting to the point that I'm considering a refund request from my recent renewal. One of the primary features for paying users is segment leader boards, yet they lean on these same users to police the boards for them. It's ridiculous.
@fifty this is related to your eBikes taking KOMs, as the rider in both situations is using a motor to power the bike or in motor vehicle whilst the activity is still active, see below ride, ride starts at the MTB park averages 20 km/h and at end of ride he forgets to stop his activity, for 7mins no speed(packing bike in car) followed by 60-75 kmh on flat road and ending at a different location to the start.
Yes...thank you Davos. This issue has literally rendered this app useless unless fixed. Your suggested fixes are well within range of being implemented. I have also flagged blatant 50-70mph error rides and with no effect which is a waste of my time.
I also suggest the following:
1. Create separate leaderboards when riders contain heart rate and watt data as well. I personally only count a KOM if I see either of these in the metrics. Without either then I just assume its someone on an E-Bike/car.
2. Side suggestion/request... I also suggest an unlock via signed waver to allow live segments with -% grade to be implemented for those who train on segments with longer durations and require live feedback despite the grade.
Just got another "uh oh!" notice. On a segment where I hold the KOM at 58 sec, and only 8 sec separates the top 10, I was "beaten" by 14 sec. On top of that, the "ride" had a max speed of 74mph and there was a *500 hour* disparity between the moving time and the elapsed time. The much heralded auto-flagging algorithm seems to need a little work. 
Or can Strava please block all activities from a user who is just recording car trips. I have no idea why they are doing it - learner maybe as on average they are actually slower than a bike - then they hit the open road... Autoflag simply does not work.
I don't have any KOMs, but I pay premium and I just want the leaderboards to be clean. My wife got a trophy this morning and I was checking out the leaderboard - completely full of cars - and this one user recording all their driving. You start cleaning a segment up and you realise just how poor Strava data is...
How is it that Strava continues to allow PBs that are ridiculously faster than the current validated WR?
People are deriding Strava for not doing simple data filtering:
https://reddit.com/r/RunningCirclejerk/s/SPhyZFJCJ7
It's annoying, not because of the people (who will sometimes do it by accident), but because it's permitted by the platform.
Strava, don't insult us by asking us report what you could filter out in a hundred lines of code and an interpolated WR lookup table.
Loving how Strava made the effort to put this forum together, but then completely ghosts it when paying members take the time to call them out on issues that a first-year software engineering intern could fix during their lunch break.
Look at this amazing segment. This is not even done by a car. It´s physically impossible. Unless... It´s on the highway that is above the tunnel and even that is completely insane 😄 https://www.strava.com/segments/18964978 I don´t even know what the actual time should be. It´s not 1:08 either, because I stopped during that ´try´. I also really love this one: https://www.strava.com/segments/9234842 Which is a small street with bumps on the road. It´s impossible to drive 75km/h . Ah well. I myself had the app on accidentally while I was on a train. No segments KOM obviously yet, my average speed was absurd high and the same counts for the max speed. 140km/h Yeah. No thanks. If I do that in real life my wife would probably kill me
The owners / management simply don't care, which filters through to the developers who are chronically understaffed now anyway.
These aren't useful examples of segments with vehicle rides because the times mostly are that short due to gps inaccuracies. Such short segments aren't allowed to be created anymore for exactly this reason. But the segments show exactly why Strava just can't go ahead and flag every ride automatically if some speeds are exceeded.
Alright thanks. Makes sense indeed. Kind of a pity. Ah well. I live quite close to the small street with the bumps so I can create a better segment there. Yeah, it´s now at least 500m. Anyway, that 172kmh is just too funny. The person who had that probably also had a good laugh about it and a strong story to tell in the pub 😄
@VincentKleijn its all in the maths and the variables used, the speed is calculated on the Segment distance rather than the actual distance covered along the segment. Strava matches your GPS data to the Segment nearest gps points to the start & end of segment and a couple other points (adhering to route).Lets look at pujadeta segment 83.2m at 4 secs(Maria KOM) the speed formula is (83.2/4)*3.6 = 74.9 kmh, Maria used an android app to record her activity, lets say she was moving at 39 kmh, its not recording every second(secs is smallest time measure), lets say her nearest point along the segment was 50m past the start and 10m past the end, the overall distance is 43.2m (83.2=-50-10) covered along segment path, the speed formula is (43.2/4)*3.6 = 38.88 kmh which sounds more realistic, when I looked at the activity its bad gps data from the map of the activity.
below image actual segment points, blue stars start & end points matched.
You would think that this awesome new algorithm would catch something like a huge spike in speed (on flat terrain) coupled with a big drop in HR, but no - this took a KOM from me. 👎 
You could, but you would be wrong 🙃
I am a runner but we are facing the same problems like riders. You would think there is a simple algorithm to tell the difference between running and car driving / GPS error but there are segments full with people finishing 300-400 meter runs in 2-3 seconds... This week I flagged a "running" activity which was actually skiing in the Alps in January and also included riding the ski lift. The same guy also recorded a 30km run which was actually cycling.
In previous comments there were suggestions to compare speed and heart rate data, but Strava obviously lacks even the basics, e.g. flag everything which is 20% faster than WR.
One strange thing I found today: someone has been notified via comment that the activity included 10 km running + 20 km car driving, he cropped the activity but still holds 7-8 segment CRs.
Reach out to Strava directly through their support channels. Provide them with detailed information about the issue, including specific examples of segments affected and the limitations of the current flagging system. Share your suggestions for improving the system and ask if they have plans to address this concern in future updates. Mobilize the Strava community to raise awareness about the issue. Start a discussion in Strava forums or other cycling communities to gather support for more robust flagging systems. The more users express concern about the accuracy of leaderboards, the more likely Strava is to prioritize a solution.
All of the above has been done by multiple people, multiple times, over multiple years. Despite the much publicized "we're improving the integrity of our leaderboards" lip service that was communicated last summer, I constantly receive uh oh notifications from athletes breaking world records. Or worse yet, I receive NO notifications and I lose segment KOMs/Cars by athletes who use the wrong activity types. I must find these segments by paying for VeloViewer Pro. This is a dead horse and Strava clearly has no interest is fixing leaderboards. Too busy becoming a social media company
there use to be Kom Defender, you would get a weekly email of all the segments that you had ridden on, from that you got a report of each segment, you could click on the activity and check it and then flag it, see below of what the email looked like
On second reading, this smells like an AI generated response, made even more suspicious by the spam link that was posted immediately afterwards.
How about having the option for have the Strava recording automatically stop when you get back to the place you started? People don't leave it on purpose when they get into the car. There are a lot of us that are not focused on Strava as we end our activity.
@Sandy there are a lot of us not focussed on our phones and we are not recording on the phone using strava app, we are using bike head units & watches, there are many tell tale signs that the bike has been put in car, low heart rate or none, pedaling cadence(zero), temperature change(heater or air cond), strava does provide the option to crop the activity and delete that car section permanently.
which brings an idea that strava could hide(like cropping) the end part of the activity as like privacy around our homes(start/end) the end would be extended further back thus it would automatically be excluded from segments without any data being deleted hey @Soren
Strava needs to hide the flag option on World Tour Pro riders rides. It sucks to see malicious people flagging rides recorded during the Giro d'Italia.
