A lot of starting/new editors ask why we don't use the railroad type segment, and do use walking trail, for example in case of railroads and other public transporation.
I would like to suggest to update this page : https://wiki.waze.com/wiki/Benelux_Railroad

With a little more explenation on why we do this:
1. The railroad type segment is not used by Waze to lock GPS-traces and as we notice there are people using Waze on public transportation, like trains, it would be a shame their GPS-traces and speed data, interfere with roads and traffic data of wazers on roads right next to railroads. For this, we want to use a segment type that is used to lock gps-traces to, and keep traffic and speed data 'clear'.

2. The railroad type segment is not visible in the app and can't be used as a navigational visual reference. Therefore, a visible segment type is preferred...

Although Global Champs have asked Waze to change this elements, it's still waiting for some follow up. Of course, when Waze changes these settings, this guideline needs to be revised.