Seasonal closures affect not only seasonal road closures (mountain passes and the like) but also closures due to roadworks. This is why the route takes you through the closure even during planning, even though Here is actually aware of it.

[Jörgen]

Ideally, roadworks closures should be treated separately from seasonal closures.

That's what I would expect, too.

[Marinus van Deudekom]

Nice find
I guess that one of the devs wel i comment on that

[ginogino]

I'd say the accuracy of seasonal closures and roadworks is correct in 3 out of 4 cases. On a road I used to travel a lot and which will now be closed for several months due to a landslide, myrouteapp web won't let me pass through it. On another road that passes through a mountain pass, it lets me pass through if I disable the seasonal closure, but that road isn't closed seasonally.
I once happened to be driving a route I usually take and while navigating, myrouteapp next kept telling me to turn back. But since I'd driven that stretch of road a few days earlier and know it like the back of my hand, I thought myrouteapp next had crashed. Instead, I discovered that that day, and only that day, the road was closed.

[Peter Zehentreiter]

@ginogino I realise that ‘seasonal’ road closures aren’t always handled 100% correctly, and I can always check elsewhere to see whether the road is open or not.

What bothers me more, however, is that although the Here map in the web planner has marked the road closure due to roadworks, it still stubbornly routes me through the closure.
The same route, when opened in the app, recognises the closure and immediately shows a possible detour.

Why doesn’t this work in the web planner as well?

[Herman Veldhuizen]

Chances are that when you use offline navigation the app works like the web based planner. But thats not what you want.

My issue related to closures is in the app. How the app guides me through or around a closure seems to depend on:

1. using online or offline maps/navigation
2. which Navigate button I press (the other one is in the inapp-routeeditor)
3. navigating a route as track or as route.

I can understand 1 (when closures are recent and only available online) but not 2 and 3. I see this happening, even when I only use the app the make and navigate the route.

[Con Hennekens]

This is know, and have never experienced it as a problem. It's actually nice to be able to disable a road closure when you see it is not there (anymore).

[Herman Veldhuizen]

@Con-Hennekens Do you have a link to some documentation if this is known? I searched and havent found it

[Con Hennekens]

@Herman-Veldhuizen, No I don't. But I have noticed before that disabling seasonal closures often leads to roadworks not being detoured. I think in the end a seasonal closure is a road closure too.

[Brian McG]

@Herman-Veldhuizen & @peter-zehentreiter this is known functionality & can actually be quite useful
using the seasonal closure function has been recomended on this forum as an answer to actually enabling you to plan a route today through a closure, that you expect to be gone in a few weeks or months

the term "seasonal" is unfortunatley a bit missleading as the function really ignores a lot of closures
the term "seasonal" is probably a historical thing thats never been updated on the web planner

if you search the forum for "seasonal closure" I am sure you will find this is not new

[Herman Veldhuizen]

@Brian-McG That the setting for seasonal closures can effect regural closures too is one thing. The fact that there are inconsistencies between the web and the app and in the app itself is another thing.
For example: When I make a route I spent most time in the inapp route editor (not the web based one) and expect the blue line which I see there to be the same when I press Navigate directly after. This wasn't the case when I last tried it.