Hi,
You may be able to use a graphic layer to emulate a buffer.
Here's how it works in theory.
1) Select the road.
2) Click a button that will create a buffer of the desired radius.
3) A graphic layer will overlay the feature, simulating a buffer.
I have personally done something similar with a point, but I wasn't trying to create buffer, I was merely putting a graphic layer on top to change the colour of the point.
I was able to set the size of the graphic layer point, that just appears on top of the feature.
This is the best I could come up with, but I don't know if this will work with lines or even intersections.
This also assumes the section of the road is a separate feature in which you can buffer/overlay a graphic layer.