The Stacked Flow reports are similar to the Flow report, but with either vehicle class or speed bin differentiation.
Total flow per integration period is represented by a stack of bars for each included class or speed bin. Fewer classes or speed bins may be required to give sufficient detail. Aggregating a class scheme (usually light, medium and heavy vehicles) often gives extremely useful results.
Another example is two speed bins, one either side of the PSL, highlighting total vehicles exceeding the PSL.