How to snap to vertex on an unstraight/uneven axis? I'm trying to mode the selected edge so that it's aligned with the vertex below. As you can see all the similar edges are uneven, made with the knife tool. 

If I hold the red arrow on the gizmo I can snap to the vertex but it would ruin my angled plane at the top of the bridge.

Does anyone know how to do this? Thank you so much!
You can keep using the knife tool then align the edge after, using "edge slide".

Edge slide is a way to grab along edges and is obtained by typing G twice.

So here:


make the cut
select the edge and use GG (double keys does not appears on the cast in the gif below) to align to the edge on the right.
then GG again to place it where you want, but this time the edge is parallel to the one on the right