Before you transport your poles, find out the local laws on overlength loads.

In B.C. the rules are as follows:

Poles may project no more than 1 metre past the extreme front of the vehicle.
No more than 5.5 metres past the centre of the rear axle.
With an Over-length Permit : 7.5 metres past the rear axle is allowed.
A red flag during day and a red light at night must be fastened onto the rear end of the load(Flashlight with red lense attached with duct tape or hose clamps).
The Balance point should be as close to the center of the vehicle as possible and should be between racks.
An inexpensive “clamp on roof rack” will suffice for tipis that measure 18ft in diameter and under.

These racks can often be reinforced, by replacing the cross bars with heavier tubing, or by sliding additional tubing inside cross bars.
Poles may be carried with the tips facing to front or rear of the vehicle, s necessary to get a good balance.