2 x 6 Handrail Cap Problem
The 4 x 6 post sticking
up creates two problems. The first is that you can snag something like a
purse or clothing on it
as you are walking up or down. The second problem will be creating a
flat spot on the 4 x 6 post with the end grain of the wood exposed to
You can already see some of the damage (cracks) starting as moisture sets on the level surface a little longer than on sloped ones.
Their are a couple of ways to fix this problem. One way is to run the 2 x 6 handrail cap over the 4 x 6 post eliminating the end grain exposure and the post sticking up creating a safety hazard.
The other way would be to extend the upper guard rail wall below the lower stringer and use one wall instead of two walls as a guard rail. The key here is to fix all of these problems during the design phase, not after it has been constructed or while it is being constructed.
Remember you can always compensate and make adjustments while you're building the stairway, but it will usually be a little easier if you can build the entire project in your mind or on a piece of paper and work everything out before you even think about starting to build the stairway.