ETA in NL wrong in the daytime - Page 2 — TomTom Community

ETA in NL wrong in the daytime

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Comments

  • MegalosMegalos Posts: 5,997
    Superusers
    IQR will use averages per 5 minutes per weekday. So it's averaged over all weeks in the 'calibration' or 'training' period (few months I guess). This means public holidays will not be reflected very well in the IQR data.
  • eddydceddydc Posts: 97 [Renowned Trailblazer]
    It is a no brainer though. Incorporate public holidays into IQR and/or let IQR not overrule the actual driving time if that's less than the IQR time.
  • iMarkiMark Posts: 13 [Master Explorer]
    The real no brainer is to plan a journey based on the current speed limits and traffic situation. On public holidays without much traffic you will get earlier arrivals.
  • MegalosMegalos Posts: 5,997
    Superusers
    eddydc wrote: »
    It is a no brainer though. Incorporate public holidays into IQR and/or let IQR not overrule the actual driving time if that's less than the IQR time.
    Yes, I mentioned it to TT about 8 years ago or so. 'Negative' delays should also be supported. Right now, if the speed is less than ~70% of the IQR speed (at night, a.k.a 'free flow'), TomTom Traffic will show a traffic delay. But the other way around it's not yet working: If speed is let's say more than 20% faster than IQR, this is not communicated to the end-user devices. If it would, it would improve already a lot. Also in your case mentioned above.
  • MegalosMegalos Posts: 5,997
    Superusers
    iMark wrote: »
    The real no brainer is to plan a journey based on the current speed limits and traffic situation. On public holidays without much traffic you will get earlier arrivals.

    I'm not sure if it's wise to base it on the maximum speed at all. For example in UK or other countries you have very narrow country roads where you can do perhaps 30 km/h, while the speed limit is 90 km/h. So using the actual speed limit is in many cases far from ideal. In principle, IQR could reflect all real-case scenarios. Only it can be tweaked indeed in some specific cases such as holiday, or when a new speed limit is introduced. But in general, I think it's better to have routing based on real driven speeds, rather than speed limits.
  • iMarkiMark Posts: 13 [Master Explorer]
    In NL we have the experience that you get accurate ETAs based on speed limits and traffic lights. TomTom adds about a minute per traffic light.
  • MegalosMegalos Posts: 5,997
    Superusers
    Hi Mark, but what about two 30 km/h roads for example, one with lot's of zebra crossings and speed bumps, and the other one without any of these? Then the second one would be much faster. Just basing ETA on speed limit and traffic light would not be correct in this case. It would be much more accurate to base routing and ETA on real driven speeds in this case. Or perhaps a road close to a school, where during beginning and end of the school day, it's very busy with cars to bring and pickup children? Also there just using speed limit and traffic lights wouldn't work. To me, using real-world driven speed limits is the better approach (if implemented correctly of course).
  • iMarkiMark Posts: 13 [Master Explorer]
    In my experience ETAs are quite exact when driving in NL. If in the map the speed limits are correct, like 30 and 50 km/h zones and about 1 minute per traffic light is implemented.

    Our experience in the UK is that you can't shave any time of the ETA if you stick to 70mph speed limit. However, on other roads we often arrive ahead of the ETA if traffic is light and we don't even reach the speed limit.

    The big difference between NL and the UK is that in the UK there are many roads where the speed limit is 60 mph and and you will never get up to that speed on a windy road. In NL most speed limits on non-motorway roads are realistically set to 80 km/h. The roads are much straighter too.
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