oil problems?

I have a 65 barracuda with a 318 and a833 . Every time I sit in traffic the oil light comes on wondering if anyone else has had this problem it flickers then comes on and when I start moving goes off.

I haven't seen any metal in the oil and I have no smoke coming out of the tail pipe. Do y'all think I should be safe and replace the oil pump . If so can u replace it with out pulling the motor?