As GDDKiA explains:
As part of the exercises, until the end of May, military vehicles will travel in almost all provinces, on motorways, expressways, national roads and other roads. Consequently, engineering structures along selected national roads have additionally been marked with military load classification signs. These signs are intended only for military vehicle drivers and have no significance for drivers of civilian vehicles.
Road authorities: – Military load classification signs – MLC (Military Load Classification) – indicate the permissible gross vehicle weight, but on the MLC scale, which differs from that used for civilian vehicles in Poland.
They add:
The movement of vehicles participating in the exercises will be coordinated in a way that causes as little disruption to regular traffic as possible. The convoys will be escorted and secured by traffic-control units of the Polish Armed Forces and the Military Police, in cooperation with the Police. The redeployments have also been coordinated with the relevant authorities, including local authorities.
What should we do if we encounter a military vehicle convoy on our way?
Road authority: – When encountering a convoy of military vehicles on the road, remember to exercise particular caution. Focus on driving rather than on additional activities such as taking photographs or recording videos. Let us heed the appeals of the General Command of the Branches of the Armed Forces and not publish information and photographs showing troop movements and their location, the dates and times of military convoy movements, or data concerning the takeoffs and landings of military aircraft. Any ill-considered activity online, or publishing photographs depicting important military facilities, installations or equipment, may have negative consequences for our country's security and defence system.
They also add:
Do not drive between military vehicles travelling in a convoy. The most important thing is for every driver to remember the great weight of military vehicles and, consequently, their longer stopping distance. Remember that military equipment is designed for combat tasks, and therefore may not have the same level of visibility of passing vehicles as civilian cars.
Where can you find information about traffic conditions on national roads?
The www.drogi.gddkia.gov.pl website and the number 19 111 are the main sources of information for everyone planning to travel on national roads. They are where we can find out, among other things, what disruptions to expect along the route. Road users can also report damaged infrastructure elements or other safety hazards they notice while driving.