4 cars per train. Riders are arranged 2 across in 2 rows for a total of 16 riders per train.
A video on the park's website contains brief footage of the Humlebien. The train has log shaped cars with "Humlebien" clearly pained on the front of the lead car. This train resembles the log design seen on a few Cavazza Diego roller coasters. The Cavazza Diego coaster has always been seen to have five cars per train were the Humlebien has just four.