We recently purchased a pair of calibrated Invar Rods and Struts to use with out digital level. We are looking for a system to carry them safely. One option that I have seen is a custom aluminum box to store and transport them in. We use 4 X 4 Crew Cab trucks with camper shell so getting them on and off the roof rack will be a chore. The other option is to use 6" PVC with a Contuit carrier kit, one for each rod. We would probably just leave that system on the truck and store the rods in the warehouse when we are not using them.
I know that a few of you have these 3 meter invar rods and was wondering how you transport them. They are rather expensive and we want to keep them in good shape. We will probably only use them 3 or 4 times a year on small projects.
The three meter rods are a flat out pain. I contacted NEDO in Germany and they manufacture a 'guitar case' sort of metal box for them, but they were almost as much as the rods. I try to stay with the two and one meter rod and not use the three meter unless it's really required.
If you find anything reasonable, cost wise and fabrication wise, please share the info here.
I've avoided the 3-meter rods for the same reasons Scott mentioned. They're too valuable to be left strapped to a standard lumber rack, but you pretty much have to carry them on top of something because they're too long to be locked inside any survey rigs with which I'm familiar.
I don't get much call for geodetic leveling -- maybe one job every few years -- so I make do with a 2-meter Nedo. It's slow with just one, and hills would be a problem, but around here the worst we have to contend with is getting on and off river levees, so it's doable.
Renting the 3-meter rods has become nearly impossible -- none of the equipment dealers I've contacted carry them in inventory anymore.
We had a giant metal box built that mounts to the roof racks on the truck. It's huge. It's obtrusive. It's a pain to get them in and out. It looks stupid. It drastically increased our vehicle height to a point that there are underpasses that we can no longer fit under... But, I didn't set it up and I don't have the say to change it. Yet. Something removable for sure would be a better bet.
This is one option. http://www.northerntool.com/shop/tools/product_200329433_200329433
We would probably take it off when we are not using the rods. This could also be a gpood way to carry 2 meter fixed height tripiods.
The other option is a custom aluminium box $$$.
I took a different approach, using RivNuts to attach a simple angle bracket. No welding required. 
