The tracks are pretty readable! I think the parts where they cross look wrong because there's no indication of the rails cutting into each other or overlapping, they just look drawings slapped onto one another. Don't forget, the cart wheels have to be able to navigate these, and the way you've drawn them, the bottom rails are inaccessible to the wheels.
I like the idea of using a pile of wood as a terminal point. However, the shading on the locks looks a little strange, why are the logs getting darker towards the cuts where they remain straight and prominent, but not towards the wides, where they'd be curving away?
On a more worldbuilding-oriented note: Anything used to stop a minecart will get banged up. Unless the logs are brand new, the cart-facing ones would not be so perfect. In addition, because they'd get banged up, it's a little wasteful to use perfectly good logs for the job. Wood that's already messed up would be a more likely candidate, perhaps with waste rock. A pile of rubble from the building of the mine was likely the most common way to build a stop, and that could include both rock and metal.
Now that I think of it - a huge consumer of wood in mines were the supports that kept the ceiling from collapsing, maybe you should add some of those. Large natural caves don't usually need them, but they also usually have very solid walls, whereas yours appear to be made of fairly loose/fractured rock. Having a realistic amount of wooden supports would probably look ugly and get in the way of the player's movement, but having some supports along the walls and on some of the pillars and outcrops would look nice.
In addition, those supports required thicker beams of wood than the rails, and those would be perfect candidates for your wooden rail terminus.