Wrong instruction list in route calculation


#1

Hi there,
I’m getting wrong instruction list trying to calculate this route:
https://graphhopper.com/maps/?point=23.11853%2C-82.42667&point=23.097087%2C-82.449324&locale=es-es&vehicle=car&weighting=fastest&elevation=true&use_miles=false&layer=Omniscale

As you can see it’s missing an instruction that indicate turn right from “Calle 34” to “5ta Avenida”. Any idea?

Thanks in advance…


#2

Hi,

at this point, you can only turn right, therefore no turn instruction is generated. If you look at a different intersection where different turns would be allowed, you see the turn instruction.

https://graphhopper.com/maps/?point=23.118427%2C-82.42659&point=23.097087%2C-82.449324

Best,
Robin


#3

I think this is wrong, because people who are not from this region do not know about these restrictions, so it is necessary to inform them properly so that accidents do not occur by not specifying well the instructions on the road.


#4

There are several algorithms / concepts for instructions generation.

  • Could set instructions at each and every path junction.
  • Could set instructions at junctions where there are >1 alternative choices. So when at a junction can go only to one way due to turn restrictions, not set an (unneeded) instruction.

It’s understandable the concern for unknown areas, though even there looking at traffic signs should lead the driver to consider only 1 way to go.


#5

You’re right, but how can I specify which algorithm to use for instructions generations? Or GraphHopper only set instructions at junctions where there are >1 alternative choices.

Thanks for the reply…


#6

I had the same trouble about this.And anelfdz did you solve it?
It is necessary for blind man to get accurate and timely instructions.How can I do some things to get instruction at each and every path junction ?I had created a new FlagEncoder that extends FootFlagEncoder for blind man.
@boldtrn @devemux86
Thanks.:smile: