If you have machine counters on all approaches, you could subtract the turning volumes from the total approach volumes to get the through volumes.
Otherwise, I doubt it, unless some math whiz can reduce it to a system of four equations in four unknowns.
"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928