Avoid ferries unless they're the only option

[SimonBradley1993]

I'm trying to adjust the car.lua profile to result in any ferry route being ignored unless it is the only option.

I've been struggling to find a way of doing this, through setting max speeds / rate / weights or penalties for using ferries. Most of what I have tried has resulted in no change (my profile changes are definitely being picked up after regenerating the dataset) in the route created.

The only thing that has made a difference is setting the ferry speed to 0 in this block route_speeds = { ferry = 0, shuttle_train = 10 },

This results in a very odd route that doesn't end at the location specified. I've tried setting the ferry speed very low, something like 0.001 but this results in a segmentation fault during the osrm-extract command, which I assume is due to the decimal point.

Are there any docs or advice on how to configure the car.lua profile so ferry routes are only used as a last resort?