Is it prohibited to reverse on a two-way road?

Why?

The fact that the road at the exit carries two-way traffic does not itself prohibit reversing onto it. When reversing, you must take extra care and give way to all other road users. If you cannot personally check that there is no obstruction behind your vehicle, you must get another person to help.

art. 23 ust. 1 pkt 3 i ust. 2 Prawa o ruchu drogowym