Air carrier Captain reported a convoy of semi-trucks crossing a taxiway in front of the aircraft; requiring a stop.

Narrative

Cleared to taxi from 1 left turn on to 2 dash line into Gate XX. Ground gave us taxi in after Aircraft Y exiting 2. Taxi instructions proceed 1 left onto 2 cleared to gate. As we began taxiing on 1 making the left turn onto 2; an airfield vehicle parallel to 1 began to drive across east to west across 2. I slowed the aircraft in the turn to accommodate the vehicle which was dangerous due to the vehicle being stopped before we began the turn. I didn't think the vehicle would try to squeeze in between the Aircraft Y taxiing out and our aircraft waiting to taxi in. As the vehicle proceeded causing us to slow; I noticed the vehicle was escorting other vehicles. I let the aircraft slow more; to my surprise the escorted vehicles were two semi trucks. The first truck was towing a heavy loaded paver on very long trailer and the second semi was a large dump truck. Realizing the trucks would not stop even though they notice our aircraft turning into them; I flashed all of the lights and came to a stop. We notified ground of the incident after allowing the trucks to pass. None of the vehicles were hit. Once clear; we continued taxiing to the gate.