i'm talking about wooden ties unva -- unbalanced. the curves in there in eureka in the first portion of the tunnel. and the tunnel is not flat. it's a 3% grade. so it's a very interesting operating environment. and what's happened during the years is a critical piece of our infrastructure that was designed and built as a streetcar operation remains designed and bit for streetcar operation and has been adapted as best we can for a modern light rail operation. so the question on the table is, ok. what is the right speed? the speed in the tunnel is 35 miles an hour. you may remember as the board a few years ago and again a real camping project is simply taking -- it wasn't a rail replacement project. it was transposing sections of rail, putting them back in and have a smoother ride due to the energy conditions that were in there at the type. does it work, fine? it does. at 35 miles per hour. factors used and if you look at assessing the determination of the speed. the switches the frog, the frog is the connection point on the rail. that