This symbol is a combination of the noun dead end, and the classifier for a team of animals. However, the straight shaft of the classifier has been modified, so that it depicts a rope. The curve
of the rope indicates movement. Hence, in this ideograph a team of animals is employed to move an obstruction.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-57 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 26: Collections in India: Suomalainen Tiedeakatemia.
I have based this symbol on Mahadevan's drawing of sign number 1100.