Problems with custom profiles

Open Source Routing Engine
1

Hi! I’m new to Graphhopper, I managed to get the graphhopper-web-10.2.jar routing engine work with build-in car and foot profiles, but creating a working custom profile seems to be impossible. I’d like to use GH for emergency vehicle routing, and i created a simple ambulance.json file containing following:

{
“speed”: [
{
“if”: “true”,
“multiply_by”: “1.2”
}
]
}

Basically I just wanted to multiply speeds with 1.2.

In config.yml I added to profiles section:

  • name: ambulance
    custom_model_files: [ambulance.json]

When importing the config, I get
2025-06-20 10:57:33.261 [main] INFO com.graphhopper.GraphHopper - version 10.2|2025-01-20T08:40:08Z (9,23,7,5,2,9)
java.lang.IllegalArgumentException: Could not create weighting for profile: ‘ambulance’.
Profile: name=ambulance|turn_costs={null}|weighting=custom|hints={custom_model_files=[ambulance.json], custom_model=distanceInfluence=null|headingPenalty=null|speedStatements=[{“if”: “true”, "multiply_by: “1.2”}]|priorityStatements=|areas=}
Error: Cannot compile expression: The first group needs to contain a single unconditional ‘if’ statement (or end with an ‘else’).

I just don’t understand what I’m doing wrong. Any ideas?

2

The same problem was answered recently here: Error creating a new custom profile - #2 by easbar

3

Maybe we could add something like “otherwise the speed might be undefined for some roads” to clarify? @Zombinol would this have been helpful for you to understand what you’re doing wrong?

4

I think I understood, but just don’t know how to get it to work…

{
“speed”: [
{
“if”: “true”,
“limit_to”: “50”
}
]
}

This works, but I don’t understand why doesn’t the following work as well? Ain’t the “if”: “true” condition always true?

{
“speed”: [
{
“if”: “true”,
“multiply_by”: “1.2”
}
]
}

5

Yes, it’s always true. But before you set the speed for every edge there is nothing it can be ‘multiply(ied)_by’, so you need to set the speed first with limit_to. There is no default value for the speed otherwise.

And yes, this cannot be seen from the error message.

6

My brain is twitching, but now it seems to work! Thank you!