Photoshopping race track curbing

[tas9195]

I am designing a race track mostly for motorcycle racing and some cars. I am trying to portray a realistic drawing of what it will look like and need to recreate the red and white rumble strips(curbing on the corners). I don't know how to draw out the curves and adjust them because not all turns are exactly round. Also it would have to have 4 sides so that I can color the red and white inside. Would appreciate any help. I put a couple of pics I saw to show you what I am going for.

 

[tas9195]

here are some actual pictures to show you