I rode the SGRT today for the first time in a while and noticed that they have improved the tunnel at the Del Amo underpass. If your heading north the approach is the same, but once you're in the tunnel you can see all the way through. If you're heading south the approach is now straighter and has a more gradual descent, you can actually see all the way through the tunnel before entering it. It's not great, but it's better than it was. Hopefully they're doing other trail/underpass improvements as well.