Faster route (green arrows) even though there is no traffic jam

sergebiro
sergebiro Registered Users Posts: 158
Outstanding Explorer
Hello,
This is not an issue per se, but I find it rather strange. Once in a while, a faster route suddenly pops up on the right-hand bar (green arrows), even though there are no traffic jams. It looks like Go Mobile suddenly "realizes" there is a faster route, even though traffic conditions didn't change. It doesn't happen after taking a wrong turn either. It usually happens when the "Avoid interstate highways" route is selected.
Any ideas?

Comments

  • Megalos
    Megalos Posts: 6,093
     Superuser
    I have only seen this when traffic changed (or, if the route was already calculated, and you start the app after a while; it needs to reevaluate the traffic situation).
  • tgold
    tgold Registered Users Posts: 2,192
    Revered Voyager
    sergebiro wrote:
    Once in a while, a faster route suddenly pops up on the right-hand bar (green arrows), even though there are no traffic jams. It looks like Go Mobile suddenly "realizes" there is a faster route, even though traffic conditions didn't change.
    How do you know that traffic conditions over the newly offered alternate route did not change?
  • Pinooo
    Pinooo Registered Users Posts: 19
    Renowned Trailblazer
    I've seen this quite often on my good old GO 1005.

    What I can think of besides the above mentioned reasons are:
    • On longer routes the driving time is based at starting time (with Live traffic and IQ routes). While driving, the device or app recalculates the route to incorporate the traffic information. Also the IQ routes information changes as the time proceeds. Could be the cause of a quicker route compared to the route calculated at start of the journey.
    • Speculation: Route calculation uses tweaks/optimizations for fast calculation of the route. Could be that details of minor roads are omitted at first. While the journey proceeds, the route gets shorter and more details (= more roads) can be taken into account for recalculating.
  • [Gelöschter Benutzer]
    [Gelöschter Benutzer] Posts: 5,321
    Supreme Navigator
    @ Pinooo
    These are exactly my "Speculations" on this issue too.
  • Uriel
    Uriel Registered Users Posts: 598
    Renowned Wayfarer
    I can think of three possibilities:

    1. Over long distances, Tomtom uses pre-calculated sections of route. It may be that as you move through the journey, additional routes are considered by the 'actively calculated' part of the routing algorithm.

    2. IQRoutes uses Tomtom's speed profile data broken into small segments throughout the day (5 minute IIRC). Either a delay or saved time could result in a faster route being calculated, based on historic data.

    3. A live traffic jam was detected on an alternative route and it cleared while you were driving.
  • [Gelöschter Benutzer]
    [Gelöschter Benutzer] Posts: 5,321
    Supreme Navigator
    For the number 1 (or Pinooo's no. 2):

    678edebf-f5c1-42d3-aabf-61a9b6ff963c.jpgTraffic diabled.
  • Megalos
    Megalos Posts: 6,093
     Superuser
    Pinooo wrote:
    • On longer routes the driving time is based at starting time (with Live traffic and IQ routes). While driving, the device or app recalculates the route to incorporate the traffic information. Also the IQ routes information changes as the time proceeds. Could be the cause of a quicker route compared to the route calculated at start of the journey.
    It's not about the IQR. IQR data is not considered for the entire route at only the starting time. Instead, the IQR data is considered at the time you will reach that part of the route (how it should be).
  • Pinooo
    Pinooo Registered Users Posts: 19
    Renowned Trailblazer
    Megalos, thank you for the explanation. So that one can be ruled out as a cause at the start of a journey :)
    However, due to delays in traffic or being faster than predicted by IQR, it still can have it's influence because of the time shift.
  • Megalos
    Megalos Posts: 6,093
     Superuser
    Yes, but the optimal route is continuously updated as far as I know. So if you're faster by 10 minutes for example, the IQR data of 10 minutes earlier will be used in the continuously updated routing.
  • Royhenryswimmer987
    Royhenryswimmer987 Registered Users Posts: 4
    Apprentice Seeker
    OK how do you accept the faster direction indicated by the twin green arrow, and how do you know which IS then faster route?