Note: I'm using the (very) old NML executable for Windows to make an NRT roadset, if that makes a difference. I don't think anything has been changed to this effect lately, but just in case, I wanted to mention it.

Expected Result

When defining speeds for some feature in km/h or m/s, the in-game speeds should be exactly as defined.

Actual Result

The displayed speeds in-game are slightly different than what is defined by the NewGRF. As an example, I've attached a simple NewGRF (and NML file) which clearly defines a roadtype with a speed of 50 km/h; however in-game the speed is reported as 49 km/h. A similar effect is observed with m/s.

This feels like some kind of rounding error or something, perhaps due to the weird units OpenTTD uses internally, but that's just an uneducated guess 🤷‍♂ Whatever the case, this probably affects other things as well, but I haven't tested that to find out.

speedbug.zip