I've been challenged by my driveway crossings through culverts. Right now I run through a total of 4 and 2 freeze up. The problem is simply that the line tends to sag inside of the culvert and sags are particularly bad where the sun doesn't shine on the line. It doesn't help that the culverts aren't pitched very much so there is very little tolerance. And, it's hard to connect the line to the wire and for the ties to stay put as the mainline is installed.
Does anyone have any tricks to share?