Indeed there is no sign indicating it's a highway, although in Belgium a divided road with 2 lanes on each side gets the same treatment as a signed highway. Here the division is missing at the weird intersection, but it's still a 120km/h road since there is no reduced speed signage ahead of time or anywhere (probably caused by mismanagement + low budget). I don't know enough about the law to tell whether it's legal to cross or not, though I would absolutely avoid it at all cost to save my life.