Route a signal to a variable

Hello,

I am desperately trying to route a signal to variable, I don't know if it is even possible or not. Bellow is what I would like to do:

Every red arrow points to a block where I could like to use the input signal "Speed" as a variable. Does anyone know how I can do that? In other word, write the input signal "Speed" to a variable with the same name, and be able to use this variable like any other that would be in the workspace?

Much thanks in advance :)