This symbol is a combination of the noun road and the verb to obscure. The top half of the road has veered off to one side, which suggests that a section of the road may have disappeared due to a
landslide. Hence, the symbol means broken road.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-949 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 92: Collections in Pakistan: Suomalainen Tiedeakatemia.