Travelling with car+caravan or camper

[Harry van der Wolf]

Hi,

When I use OsmAnd with car+caravan or camper and set a max. speed of
90 kmh or 95 kmh, and plan a route to a camping in France, I prefer it
to take the highways and also the "route peage", so the toll roads to
be there as fast as possible.
I know from experience that this is much faster, especially with
caravan, then taking a route over a shorter way being the "Route
Nationale".
With the old route mechanism (A* and A* x2) I could tweak the routing
parameters by giving "massive priority" to toll roads that, despite
only travelling at set 90 kmh, it would still take the "route peage"
(with topspeed of 130 kmh).
Theoretically the shorter route over RN roads is faster. In practice,
it is much slower. I consider this a flaw in the routing mechanism and
priority setting. It is not simply "less kilometers per hour over a
shorter route = shorter travelling time" is better than "more
kilometers per hours over a longer, but much more optimized route".
Going with caravan or camper through small villages with traffic
lights and other hindrances takes in practice much more time.

I did read the blog at https://osmand.net/blog/fast-routing/ . Very
nice and informative read.
If I prefer to really stay on the toll roads with my caravan. How do
I do that with the new maps/routing. Can I still adapt the routing.xml
(https://github.com/osmandapp/OsmAnd-resources/blob/master/routing/routing.xml)
or does that no longer work? I see that the "Heuristic Coefficient" is
still deactivated
(https://github.com/osmandapp/OsmAnd-resources/blob/master/routing/routing.xml#L393C8-L393C61)
and thereby using the 1.0. But the new routing is indeed much faster,
so is that routing.xml still even valid?

OsmAnd is now unusable if I really want to stick to highways and toll
roads. Or I should take normal car profile and calculate every arrival
time with 10-15%.
Next to that: Truck/Camper and caravan lets you specify height, width,
length, weight, etcetera, which is very convenient, but also with a
big truck you really want to stay on the toll road and definitely not
go through small villages.

Best,
Harry

[Greg Troxel]

Harry van der Wolf <hvd...@gmail.com> writes:

> With the old route mechanism (A* and A* x2) I could tweak the routing
> parameters by giving "massive priority" to toll roads that, despite
> only travelling at set 90 kmh, it would still take the "route peage"
> (with topspeed of 130 kmh).
> Theoretically the shorter route over RN roads is faster. In practice,
> it is much slower. I consider this a flaw in the routing mechanism and
> priority setting. It is not simply "less kilometers per hour over a
> shorter route = shorter travelling time" is better than "more
> kilometers per hours over a longer, but much more optimized route".
> Going with caravan or camper through small villages with traffic
> lights and other hindrances takes in practice much more time.

There are two separate things going on and I think you may be blurring
them.

One is the search algorithm to choose among route candidates. There is
a right answer and the question is the cpu cost of finding a route and
then how how close that route's metric is to the best metric value.

The second, that I have mentioned before, is that for a given proposed
route (a list of how to drive from here to there), one must compute a
metric. In theory, that metric (most used) is the time it will take.
You are esentially saying that these time estimates are wrong.


What's needed is to be able to output the route in great detail and then
record what happens so that one can see how the reality lines up with
the estimate. It could be that the time cost of stoplights is
underestimated. It could be that the time cost of stoplights in your
vehicle is higher than in a normal car. The relationship between
maxspeed (capped at vehicle speed) and actually achieved speed may be
off. All of this is tricky.


I will repeat my usual plea: Do not use the word "penalty" to describe
anything that is fundamentally about producing a correct travel time
estimate. If a traffic_signal results in an average delay of 90s
compared to driving straight through at speed, then adding in 90s is not
a penalty. It's an estimate for the time to drive the route.


If on the other hand you the human say that you do not like traffic
lights, and you prefer route A that has 8 lights to route B that has 9
lights, as long as A takes not more than 2 minutes longer, then that is
fair to call penalty, as you move from "time to travel" to "time to
travel adjusted for a fake time cost for things I don't like".

Personally, I often choose routes without scary left turns (we're drive
on right), or other intersections that feel dangerous. I avoid roads
that will have congested exit ramps (link roads) and especially backups
before them. A crash is very costly in terms of time, both in the
moment, repairs, etc. so I lean to "min probabilty of crash routing".