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Why routing alogrithms from different maps don't always give the same route

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Re: Why routing alogrithms from different maps don't always give the same route

#21

Post by Angostura »

dottedmag wrote: post #7

I'd love to have knobs "how experienced driver I am" and "how familiar am I with the area" (this one can even be automatic, given the amount of data map app makers collect!) for the map apps. If I'm in an unfamiliar area, I really don't want to theoretically save a few seconds by taking a shortcut via little maze of twisty passages, all different. Just give me a straightforward route using a highway, please. (edit: t…

Apple Maps does this for me, when cycling - 'fastest, simpler' routes are displayed, along with options to avoid hills

Re: Why routing alogrithms from different maps don't always give the same route

#22

Post by karussell »

errcorrectcode wrote: post #13

Ignoring optimization goals such as time, cost, distance, road type, and safety: It's not economical to solve the TSP perfectly for real-world problems, so heuristic algorithms are used to deliver good-but-not-perfect solutions(s).[0] 0. https://en.wikipedia.org/wiki/Travelling_salesman_problem

The article is about solving a A-to-B routing problem, for which you would use something like a Dijkstra algorithm, which is not a heuristic (in its standard settings) and has nothing to do with solving a TSP.

Re: Why routing alogrithms from different maps don't always give the same route

#23

Post by tda »

kortilla wrote: post #18
0xTJ wrote: post #2

I used to wonder how companies like TomTom stay in business, given how big products like Google Maps have become. More recently I've seen some media that showed off one of those stand-alone GPS devices (I don't remember which brand, but likely TomTom or Garmin), and I was blown away at how far they've come in capabilities and user interface. (I'm sure it's not just that, looks like they've got a lot of other products…

Google maps is exceptionally limited to the point where it’s very easy to beat on mapping features so there is a lot of room for competitors to survive in various niches. - The offline experience is garbage. Default behavior should cache large routes offline immediately when I’m on WiFi. - partial connectivity experience is garbage. Stalled map loads, freezes, etc while driving through a 1x cell service area, even if…

And still, even though I pay for the TomTom app on my phone I have switched back to using google maps as default: It loads way quicker, and I only have to type a few letters and it suggests what I meant (even if i made a few typo's). Search is almost instant. Traffic information is good enough. And I can quickly load a satellite picture if the destination is unknown and it is e.g. unclear which side of the lot the entrance is on.

TomTom has better traffic information, way better guidance on complex roads (google maps will tell me to take the exit, and it small font it says 2400m, which is the next exit). It has better traffic cam warnings, shows max speed more reliably etc.

But also it is slow and clumsy to search for a destination, especially if you do not have the exact address (like a shop by name).

As I have practically unlimited data and good coverage everywhere I go, offline maps are more of a drag than a plus. Just saw amigo mentioned, will check that out now

Re: Why routing alogrithms from different maps don't always give the same route

#24

Post by dikei »

0xTJ wrote: post #2

I used to wonder how companies like TomTom stay in business, given how big products like Google Maps have become. More recently I've seen some media that showed off one of those stand-alone GPS devices (I don't remember which brand, but likely TomTom or Garmin), and I was blown away at how far they've come in capabilities and user interface. (I'm sure it's not just that, looks like they've got a lot of other products…

Tomtom is selling data to businesses that require raw map data to build their own apps like ride haling service, delivery service, etc..

Re: Why routing alogrithms from different maps don't always give the same route

#25

Post by [deleted] »

errcorrectcode wrote: post #13

Ignoring optimization goals such as time, cost, distance, road type, and safety: It's not economical to solve the TSP perfectly for real-world problems, so heuristic algorithms are used to deliver good-but-not-perfect solutions(s).[0] 0. https://en.wikipedia.org/wiki/Travelling_salesman_problem

[deleted]

Re: Why routing alogrithms from different maps don't always give the same route

#26

Post by leokennis »

dottedmag wrote: post #7

I'd love to have knobs "how experienced driver I am" and "how familiar am I with the area" (this one can even be automatic, given the amount of data map app makers collect!) for the map apps. If I'm in an unfamiliar area, I really don't want to theoretically save a few seconds by taking a shortcut via little maze of twisty passages, all different. Just give me a straightforward route using a highway, please. (edit: t…

Yes! Apart from the standard "fastest" and "shortest" options and your suggestion, I'd also love:

* Scenic routes (i.e. navigate as far away from buildings and as close as possible to water, forest)

* Least polluting routes (i.e. least amount of traffic lights, most time spent in the optimal "speed vs. pollution" of your car)

Re: Why routing alogrithms from different maps don't always give the same route

#27

Post by kwhitefoot »

The thing that annoys me about most routing solutions is that they do not allow me to choose between fastest and most economical routes and they don't allow me to disallow classes of road.

For instance Tesla's in car routing is pretty good for getting somewhere quickly so long as all the roads alog the way are of good quality. But if there is a single lane country road that cuts a few minutes off a journey it will quite happily send me down it regardless of how suitable it is for a larger than average car with only 13 cm of ground clearance (Model S).

I can tell it not to use motorways (perhaps because I want a scenic route?) and ferries (because they are expensive) but I can't tell it to avoid unmetalled roads.

Most of the others that I have tried aren't much better.

Re: Why routing alogrithms from different maps don't always give the same route

#28

Post by srmarm »

I believe google maps now automatically factors in carbon footprint when suggesting routes now [0]

Time will always be a nice easy to quantify way of comparing routes but as someone who generally doesn't have to get places quickly I'll usually prioritise a more pleasant journey over the shortest one - so many (personal) ways to define that and not so easy to quantify!

Personally I've had some great drives where google maps has a 'x mins longer' route show up that I can see goes down some twisty country road vs the boring main road.

[0] https://www.theguardian.com/technology/2021/oct/06/google-ma...

Re: Why routing alogrithms from different maps don't always give the same route

#29

Post by fabioborellini »

Doctor_Fegg wrote: post #10
ajuc wrote: post #9

Earlier quoted context omitted.

This, but for biking and without a knob. Make an econometric model of my previous recorded routes with explaining variables: elevation, distance driven already, time driven already, time of day, temperature, road quality, wind direction, rain and explained variable: speed for the next kilometer. Predict my speed on potential routes based on that. Calculate routes taking these predictions into account.

brouter.de is amazingly customisable for bike routing. The trade-off for customisation/personalisation is slower calculation times. Most fast routing algorithms work by precalculating the best routes, which obviously doesn’t scale if everyone has their own “best”. (I run cycle.travel, which prioritises one good, opinionated routing model over customisation.)

cycle.travel seems lovely!

Re: Why routing alogrithms from different maps don't always give the same route

#30

Post by tgb »

leokennis wrote: post #26
dottedmag wrote: post #7

I'd love to have knobs "how experienced driver I am" and "how familiar am I with the area" (this one can even be automatic, given the amount of data map app makers collect!) for the map apps. If I'm in an unfamiliar area, I really don't want to theoretically save a few seconds by taking a shortcut via little maze of twisty passages, all different. Just give me a straightforward route using a highway, please. (edit: t…

Yes! Apart from the standard "fastest" and "shortest" options and your suggestion, I'd also love: * Scenic routes (i.e. navigate as far away from buildings and as close as possible to water, forest) * Least polluting routes (i.e. least amount of traffic lights, most time spent in the optimal "speed vs. pollution" of your car)

Google Maps now defaults to that last options (or at least displays it by default, I'm not certain it's always chosen). See here [1] for example. I would be interested in seeing a 3rd party assess how accurate that metric is.

[1] https://techcrunch.com/2021/10/06/google-maps-launches-eco-f...

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