(a) Excepting as otherwise herein provided, the driver of a vehicle approaching an intersection shall yield the right of way to a vehicle which has entered the intersection from a different highway and when two (2) vehicles approach or enter an intersection from different roadways at approximately the same time, the driver of the vehicle on the left must yield the right of way to the vehicle on the right.
(b) The right of way rule declared in subsection (a) of this section is modified as stated in this article. (M.C. 1963, § 20-308)