Firstly, you guys can see speed limit distribution on the following route:
And on the same link, you guys can see the average speed that the car goes (you guys can see that even in unrestricted sections, there’s an 120 km/h speed cap on the car by default!)
So, is there a way to create a custom model that removes the car speed cap and/or bypasses the existing speed limits? And btw, I’m relatively new to the website, having just created my account today.
If it is not possible, why is the car speed capped to 120 by default even on unrestricted sections on the map?
You can certainly have a car speed higher than 120km/h. The question is if this is a meaningful assumption in general, but even for unrestricted road sections the average speed is not necessarily higher.
Anyway. To do this you could either modify the car_average_speed directly in the car.json e.g. with a factor like "limit_to": "car_average_speed * 1.1".
Or, you change the defaultSpeedMap in the Java code (CarAverageSpeedParser.java).
And will a new custom model that could remove the car speed cap be planned/added in the future?
Currently there are no direct plans.
Also, I’m on a regular free account. How can I run the modified GraphHopper on mobile after modifying the car average speed?
Not sure what you mean. You can use or modify a custom model via clicking on the gear button in the top left and use the resulting link in any browser.
I meant that after modifying the car average speed in the code, how do I run the GraphHopper maps and considering the modified average speed code on iPad?
And by the way, I have evidence that the 120 km/h car speed cap is evident even in the navigation version of GraphHopper. So, this is the unrestricted stretch of the Autobahn with the normal max speed setting:
I can see that the car average speed is the same in both images, and even the ETA time from the heart of Germany to Dresden is literally the same! So, does this mean custom models alone can’t bypass the car speed cap (120 km/h)? And if it can’t be bypassed by custom models alone, why?
Yes, sure. It uses the same servers and has this same limitation, which comes from the fact that we use a certain algorithm that speeds up the response time by a lot. But also comes with this restriction. Disabling this algorithm would lead to a normal A* algorithm which might be much slower but without this limitation. (Unfortunately you cannot disable this feature via the UI)
What I meant was the “navigation” feature which is present in this version and could be used for turn-by-turn navigation on mostly any device with GPS support.
It is not possible for users of GraphHopper Maps yet, but for paying customers we can make it working. Or you could host your own server and make it possible too.
You can only use the existing profiles like car, bike, etc. To create profiles based on completely different transportation modes you could create them from scratch but not in GraphHopper Maps as it is. (again this is possible but only for paying customers or if you setup your own server)
And by the way, I calculate the recommended speed of a road in GraphHopper by multiplying the speed difference between the two fastest vehicles of the route by 70% and by adding the second fastest vehicle’s speed in GraphHopper… So, if the fastest vehicle (car) goes 120 km/h (top speed) on average on a Autobahn, can I ignore the speed cap and assume that the car average speed is higher than that (150 km/h, for example)?
