Sectional Track Problems

I have alot of this sectional track, that I no longer use due to the bent edges at the track joints. Most sectional track pieces have a higher sidewall than the seamless track, (not sure about the newer sectional track with the arrows cut out in the center). But I have the older style track, which has caused me problems with slowing cars down, to creating wrecks, due to the bent and uneven edges.

I was trying to cut the sidewalls down with a knife, but couldn't get a even cut. If this could be done I really believe it would eliminate the above problems. Any ideas on how to cut the sidewalls even without messing up the track?

Preacher