Because in those days Taiwan's coastal railway had not yet been built, Yuanli did not have good transport links with the outside world, nor did it have any export traders. Tachia on the other hand had Ta-an Harbor through which products could be shipped for export by sea, and it was linked by a sugar refinery railway to the mountain railway line, enabling products to be sent for sale all over Taiwan.
由於當時台灣的海線鐵路尚未闢築，苑裡的對外交通不便，而且也沒有出口商；反觀大甲有大安港，對外海運及對內糖廠鐵路連接山線鐵路運銷各地，於是大甲便成為苑裡帽蓆的集散地。