Frans, it makes perfect sense to me that a route will change when I change the basic criteria for the choices CT makes, especially with such a restrictive option as 'Routes'. 

However, the idea of maintaining the integrity of an existing route while adding a section with different criteria (for example, a gravel section on an otherwise paved route, or a non 'Routes' option on a long 'Route') already exists. Unfortunately, it involves viapoints. 

If you're not aware, the dialogue box that appears when we click on a VP contains many powerful features. The 'Go' feature might just become a good friend. 

Sorry for responding late, and thanks for your reply.

It does also make sense to me that the route changes. Then again it also makes sense to keep an existing route as is when changing the routing criteria and only apply it to the modifications afterwards.

Of course I can fix it by adding Via points, but that is a bit cumbersome, hence my request.

Frans, 

It does also make sense to me that the route changes. Then again it also makes sense to keep an existing route as is when changing the routing criteria and only apply it to the modifications afterwards.

How does that work exactly? How does CT know when I want it to apply my criteria (Routes, Paved etc.) and not? Am I adding day 15 to my tour or am I diverting to a campsite on day 14? 

Fortunately, we can tell CT when (and what sections) to 'ignore' our routing preferences. That is done using the 'go' feature as highlighted above. One viapoint is necessary. One subsequent click. More info here: https://cycle.travel/help/route_planning/route_types

Frans is wishing to freeze the current solution, except for a bit in the middle (or at start/end) which is unfrozen and to re-plan that on more liberal route type setting.

I can't see how the Go options for Via Points would permit that, but am v happy to be coached. SFAIAA, at present it entails first inserting Via Points to pin the solution arising from the Routes setting, then changing the setting and dragging the route to make the desired deviation or extension. However, on a long route, it could take a lot of VPs to ensure there was no unwanted drift in the section that is desired to stay unchanged. 

It seems to me what Frans is wishing is a solution built up by a concatenation of separate sections. As I understand it, that is pretty much how the software works in finding solutions, except that currently it does not cater for a blend of route type settings. 

So, it would seem conceptually possible for the software to cater for what Frans wishes, something like this: "Starting with a route that has already been saved: freeze solution except between this added special VP and the one that currently is next (if any); allow unfrozen section to be dragged and re-planned according to the specified revised route type setting".  (There would need to be some way of indicating that the revised solution was a hybrid, perhaps by allowing both Routes and Any to be highlighted if the route contains a special VP as above.)

Obvs, that could be a lot of software development, so whether Richard has any appetite to do it is for him; esp considering the perhaps greater benefits from other use of his time (eg doing some cycling!)

Simon, I take my hat off to your mind reading skills. Given that the OP posted no example and was vague in terms of the length of 'shortcut' or extensions I pointed them in the right direction.

The OP stated:

However sometimes I do want to modify the route given, e.g. because I want to use a shortcut or add the part to my start or end point.

There is no problem adding to the start or end point.

In relation to:

Frans wishes, something like this: "Starting with a route that has already been saved: freeze solution except between this added special VP and the one that currently is next (if any); allow unfrozen section to be dragged and re-planned according to the specified revised route type setting".

The following may help:

This is a route (plotted using 'Routes' from Teruel to Valencia. Now, imagine I want to go to Bétera (about 150 km) - I cannot plot a route (to Bétera) because 'Routes' is the active choice.

T Val 1 is the same route, but now I have added 2 viapoints - one at the last point I really want to see on my original route, the other at the next point I really want to see further along my original route.

In T Val 2 I have now added viapoint 3 (between the 2 previous points) and dragged that to Bétera. CT has now calculated a route that keeps me on my original route to my specified point, takes me (using different criteria to 'Routes') to my diversion and then gets me back on my original before I needed.

I'm the designer - do I really need to be reminded that the diversion is not 'Routes'? If so, I can add a note to myself in the viapoint - visible in most gps devices and PDFs.

CT has many powerful tools, and in my humble, this is one of the strongest, especially for those that are very specific about their needs and preferences. It is incredibly versatile. But cumbersome. Apparently. 

No mind-reading, I'm just trying to see the world through someone else's eyes. Most of us don't always express ourselves 100% accurately.

In seeking to replicate your example, I find I can't drag the inserted VP via Betera if the route type remains as Routes. Yet your example seems to achieve it; what do we need to do to permit that?

(I can drag the route if I first change the specified route type to Any (or Paved), but that causes changes in the route; eg around Viver. It's that sort of thing that seems to be what Frans is seeking to avoid, understandably IMO.)

Try using the 'Go & Any' feature on the first viapoint. 

Thanks, I understand now. So CT already caters for what  Frans seems to be after! You just need to know how to do it ...

So CT already caters for what Frans seems to be after! 

Yes. As was said in the very first reply. 

You just need to know how to do it ...

And perhaps to be less adverse to viapoints.

Well Simon indeed envisioned what I wanted

The situation I encountered was when planning a multi-day trip.
I used Routes to create the trip, then split it into days. The place I am staying is not on a Routes section, so I changed to Any and suddenly my route changed,whereas I only wanted to add a section in Any to be able to get routing to my overnight stay.

Triggered by the suggestions of Hobbes, I did play with via and go but somehow I fail to see how I should do this.
I have made this testroute:
https://cycle.travel/map/journey/1044852

This is with Any. 
But actually I wanted to use Routes because that often gives nicer routes, and also gives signposted routes.
When I switch to Routes the route changes (expected) but also the begin and end locations are moved because they are not on a place where a designated route is.
It would be nice if the routing would add a segment from the original start position to the place where the Routes routing starts. Same for the end.
Or if there was a way to add this. I did not find a way to do this, not even when playing with via+go, so if it is possible, please educate me!

The other issue I mentioned was shortcuts. I'll use the same example. WHen using routes I see:

Now I happen to know that the unpaved path is in a bad condition after rain, so I would like to introduce a shortcut by using the red road SE of the unpaved section. In this specific case Any would give me the route I wanted (so maybe this is a bad example) but I would not know how to plan this using via+go.

And of course I can envision ways to circumvent this. E.g. the start/end thing could be solved by just adding another route to the beginning and yet another one for the last section to the final destination but that is not really user-friendly.

Appreciate your suggestions (and apologies if I misworded things. English is not my native language)

Frans

Hobbes message of Fri 3rd July at 1700 gives the advice.

To achieve the "mid-route shortcut", insert a Via Point at the end of the section that you wish to freeze, and on that open the VP menu, then click on Go "Any way". Also useful to add another VP at the start of the section after your desired diversion. Then, drag the route between them to go via the desired diversion - this will be on "Any" surface, while leaving the rest of your route frozen to the setting it had before.

I don't think there is a way to do the equivalent add-on at the start or end of a journey (though we would all welcome some explicit coaching if there is). A simply work-round would be just to make the add-on a separate journey. 

(The thing that I was not working out was that it is the VP at the start of the diversion that needs to be set with "Go any way" - that doesn't seem intuitive, at least to me, and had not been explicitly mentioned.  

Frans, your example does not work for me. The start and end points do not change by selecting different criteria: Paved/Routes etc. 

Also, I don't understand what you want to do because it is not clear where you want to end the route. 

By the by, your part of the world is quite probably the part where 'Routes' is the most unnecessary since it has more than the average number of (pink) cycle routes. 

Nevertheless, I will attempt to demonstrate how to add a start point and end point that are not on a 'Routes' section. I am deliberately choosing a ViaVerde in Spain between Segovia & Valladolid. The campsite in Segovia is not on a 'Route' and the ViaVerde only runs 3/4 of the way to Valladolid.

Here is my first draft, using 'any' and simply selecting the towns as my start & end points. I am displaying the OpenCycle Map to make the ViaVerde (purple) more visible. (You may see the standard map as you're not a subscriber).

Here is the ViaVerde section, plotted using 'Routes'. (I cannot plot the full route using Routes).

The first step is to add my 'real starting point' - the campsite in Segovia.

Add Viapoint 1 & 2 (on the Via Verde, next to my original start point) Note: the order is important! VP 1 will become my new start point.

Click on VP1 and select 'Go anyway' 

Now, Remove the (Green) Starting point (you're left with only 1 VP)

Now we can move the (green) VP anywhere we want (whether on a route or not - like the campsite)

Here is that route (VV3)

So, we have a 'Any' section to the start of a 'Route' section. But we still need to navigate to our destination where there are no 'Routes'.

Add a VP (VP2) just before the original destination

Click on VP 2, choose 'go anyway'.

We can now move the 'Checkered flag' destination point anywhere we want. 

Here is that route. (VV4)

As for adding an 'Any' section in the middle, that was covered previously, above. 

Now I happen to know that the unpaved path is in a bad condition after rain, so I would like to introduce a shortcut by using the red road SE of the unpaved section.

I'm confused. You clearly know to avoid this when wet. Is a 'back up route' necessary? Can you not make two versions - one wet, one dry? We can use markers to remind ourselves. Or, you know, engage our brain and ride the safer way. 

The next time you have a question, please post a real world example. 

I've just realised that I've included an incorrect link above: Adding the campsite at Segovia is VV3 here.

@Hobbes

Wrt my example: if you load the tour and look at the start point you get this:

If then I press Routes the starting point moves to a cycle route. See picture

The end point also moves. I feel that the start and end should not move iresspectively whether I have chosen Any/Paved/Gravel/Routes

About the unpaved path: I can definitely make two routes. That is not the problem. Actually I know this track well enough to be able to cycle it without navigation. This is a made-up example.
I'm not really sure when I bumped into this. Maybe when planning in France wanting to combine two routes/ If you stick to Routes it gave a large detour to the place where the routes intersect. But as you so kindly explained using the via points and Go Any can be used to change this. Thanks a lot!