Crucifixion on a cross was not just Roman or Jewish. It was supposedly devised by Semiramis. This was an ancient type of capital punishment used by the Scythians, Romans, Persians, Greeks and Germans.
It was considered the most shameful and disgraceful form of capital punishment by the Romans and was reserved for assassins, rebels, and slaves that turned criminal.
There were three types of crosses. There was one that was in the form of an X another was built like a capital T. The other type which is mostly seen today looks more like a non-capital t or t.
Surprisingly most crosses were only a about ten feet in length. This meant that the criminals feet were less than two feet from the ground. Paintings and movies that show Jesus hung high in the air gives the wrong idea of reality.