Using a Normal map together with a Bump map I've been stressing these days searching for a video on using a Normal map with a Bump map, but I haven't found something good. Some suggest connecting the Bump input into the Displacement output and others suggest connecting it to the Normal output of a Shader (both using a Bump node). What would be considered a right way of doing it? The Bump node has a Normal output. Is that for the Normal map?

I have this road scene where the bricks are too smooth and I would go for making them more bumpy - 

I want to use the Noise texture as a Bump map, but the bricks already have a Normal map so that I have no idea where the bump node should be connected. And when connecting it into the Displacement output nothing happens.

In a tutorial by Andrew Price called "The Secrets Of Realistic Texturing", the Normal map is connected into the Displacement output, but I'm not sure if it is a good way of doing it and the bumps are more like some streched lines which is not what a Noise texture would do - http://qgv6y6drlr2sy3es4blouyvd9.wpengine.netdna-cdn.com/wp-content/uploads/sites/3/2013/01/complete1.png

Here's the file if anybody comes up with something - http://www.pasteall.org/blend/31902

I'm unable to upload the maps (too high resolution), sorry. But, you can use maps of your own.

Here's the node setup -
This is the correct setup to combine normal and bump maps.

If you use a normal map, you can't use the displacement material output, you have to plug it directly into the BSDF. The normal map must go first, and then you can add bump mapping on top of it.