@davidzipper the correct sign is this:

Sign 251: Cars banned

- Tho for the most part you see Sign 250: which is just the red ring on white background, banning all traffic.

Not to be confused with Sign 331.1 signifying a Motor Vehicle Road that like Highway are only allowed for use by vehicles that have a mximum speed of at least 61km/h, but unlik a highway do allow for level crossings and traffic lights!