Traveling assistance system for agricultural machine

A traveling assistance system for an agricultural machine, the traveling assistance system comprising:

• a position detector to detect a position of an agricultural machine to which a working device is attachable;
• a criterion creator to, based on the position of the agricultural machine detected by the position detector, create a determination criterion located forward of the agricultural machine for determination about a turn of the agricultural machine;
• an area identifier to identify a first area and a second area, the first area being an area which is a first portion of an agricultural field and in which the agricultural machine travels in a predetermined circumferential direction and the working device performs work, the second area being an area which is a second portion of the agricultural field, which is adjacent to the first area, and in which entry of the agricultural machine is prohibited in advance;
• and
• a first setter to, in a case where the determination criterion is located in the second area, set a first turning portion at a position in the first area and between the agricultural machine and the second area, the first turning portion being a portion in which the agricultural machine makes a turn.