Bad time estimation while using LoRouter for cycle profile touring

Georg D shared this problem 21 days ago
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I used LoRouter Online to navigate me from 47.92837,7.35812 to 48.003119,7.26396 and it over estimated the travel time by 1/2 or 1/3 depening on what one looks at.

At 13:49 ETA was 15:03 (=74min travel time) but real arrival time was 14:43 (=49min moving time plus 5min break which router shall not take into consideration) so routing engine over estimated by 74/49=51% which is IMHO considerable – it easily makes the difference wheter I do a tour or not. I used profile Touring with "average speed on flat ground" set to 20km/h and the track's average speed while moving is 19,0km/h so I was quite nearby the setting.

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The over estimation is only partly caused by 240m elevation gain over 3,7km uphill distance. For the part containing the uphill portions, LoRouter estimates 42min while I needed 25min, so the conversion from "average speed on flat ground" into watts into "uphill speed" over estimates by 68% – which is discussed in another issue.

For the remaining part, LoRouter estimates 74-42=32min while I needed 49-25=24min so still an over estimation of 32/24=33%. What can cause that and how can we improve that?

Side note: For hiking profile, ETA was very exact during a few tests. So it is not a general issue but limited to some profiles.

Replies (1)

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Hello Georg. I know you have recently reported similar issue with ETA for cycling. I did look into it. What is going on there: If I say I cycle 20 km/h on flat ground, this speed is converted to wats. This part is working reasonably accurate. Then this power is used for ETA/time calculation. These are calculation done by Brouter authors, not me (us) and frankly I do not see problem at the first glance. Some more work is needed. Most likely some constants (weight of the system for hills factor) are not right. Thanks for reporting, I do not dismiss this issue, it is a problem. Walking: Here the approach is different. We use Tobler hiking function with some Locus-custom extension for surfaces. Anyway thanks for reporting.

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