On Wednesday, April 29, 2020 at 10:58:24 AM UTC-7, Bob LaFrance wrote:

I am looking at putting up 18 street lamps along the driveway. Bases will be made of concrete...

I am concerned that rebar might not be able to stand up tho as it isn't constructed of high grade steel.

I'm told that the steel in rebar doesn't take welding well, it gets brittle, so a triangular
truss wouldn't give a nice stiff post either. Actual lamp standards are usually
spun aluminum (inexpensive cold-worked metal) with bolt-pattern bases that are
relatively easy to join to a concrete footing.

I'd buy something like that, not build.
Start by looking at parking lot lamps, and note any brandnames on the parts?

Other possibility: you might also want to consider
low-level lighting (short posts, light directed down onto path/roadway).

How would these fit into the Granite state?
https://www.alibaba.com/product-detail/Grey-Lantern-Japanese-Garden-Pagoda-Stone_60231251289.html