It's a bit messy really.
Why do you have 2 different boards just before T1, especially as one hides the other?
Curves are badly done, and straights change width quite a lot.
I thought it could do with some improvements, so I've made some alterations to show what I mean. See attached, where I've redone the large curve...
... and I've made a curve that I would have used at the inside curve beside the overhead start lights (haven't put it in place - just put it beside your curve so you can see the difference).
I've also moved Split 1 (blue line), as it's far too soon - I've moved it to where track goes from armco to barrier at both sides.
Some tips:
You don't need split lines so big - use W to make them smaller - they only need to be big enough to reach over both edges of the track.
When doing curves, better to use
more Armco1 rather than
less Armco5, as it makes any curve a lot smoother.
Also, if you're going to make a curve using the barrier long, then as this barrier is just smaller that the 1st chalk line, you should lay out the chalk first to make the best curve you can by adjusting when looking straight overhead, then once you're happy with the shape, overlay with the barriers, then remove the chalk.
Sometimes it's best to do the inside curve first, then use the D (distance marker) tool to work out outside of curve, especially if you want the barriers same distance apart throughout the curve.
On a positive note - it's nice to see someone else willing to make layouts