what does a private citizen need to drive a rental truck for commercial purposes

[NE2]

Yes, Florida has ag checkpoints, mostly at the St. Marys and Suwannee Rivers. There are a few minor paved roads that avoid them (CR 120/Reynolds Bridge or CR 121 west of Hilliard) but otherwise all paved routes into the Florida peninsula pass one.

[agentsteel53]

California aggie points can be trivially easy to avoid.  I avoid the one on I-15 coming back from Las Vegas by taking the Harvard Road exit to old US-91/466.

with regard to the Florida ones: there is a white guide sign somewhere on one of the "shunpike" ways to get around a particular inspection station ... and when I stopped in the middle of the night to photograph it, a sheriff approached me.  I think he was posted there to catch evaders.  (he didn't care much about me once he figured out I wasn't stealing the sign.)

[Ace10]

There's a white guide sign on I-10 Eastbound just past the FL-AL state line:

https://maps.google.com/?ll=30.572293,-87.408299&spn=0.000037,0.021479&t=m&z=16&layer=c&cbll=30.572447,-87.40883&panoid=cTC5W7LRExqf5wGLLlfFwg&cbp=12,144.8,,1,-2.02

"Warning: No bypass for loads with agriculture, horticulture, aquaculture"

A sign just past that one reads "All trucks, trailers, rented trucks, trailers, commercial, cargo vans, next right."

https://maps.google.com/?ll=30.572109,-87.407699&spn=0.000037,0.021479&t=m&layer=c&cbll=30.572013,-87.407405&panoid=cIAAZjSumTfOG35DKLkslQ&cbp=12,151.9,,1,2.57&z=16

Going eastbound here, there looks to be a separate agricultural inspection station and weigh station. There's a weigh station westbound, but no agricultural inspection station. Yet the signage eastbound makes it seem like they are two separate weigh stations, so I'm not too sure what's going on here. Last time I drove this stretch was about three months ago, but my memory is cloudy.

Anyway, I know the OP isn't driving through Florida, but it's helpful to know if there are states that do require rental trucks to enter weigh stations, and to know if states have any specific requirements for carrying CDLs.

[realjd]

There's a white guide sign on I-10 Eastbound just past the FL-AL state line:

https://maps.google.com/?ll=30.572293,-87.408299&spn=0.000037,0.021479&t=m&z=16&layer=c&cbll=30.572447,-87.40883&panoid=cTC5W7LRExqf5wGLLlfFwg&cbp=12,144.8,,1,-2.02

"Warning: No bypass for loads with agriculture, horticulture, aquaculture"

A sign just past that one reads "All trucks, trailers, rented trucks, trailers, commercial, cargo vans, next right."

https://maps.google.com/?ll=30.572109,-87.407699&spn=0.000037,0.021479&t=m&layer=c&cbll=30.572013,-87.407405&panoid=cIAAZjSumTfOG35DKLkslQ&cbp=12,151.9,,1,2.57&z=16

Going eastbound here, there looks to be a separate agricultural inspection station and weigh station. There's a weigh station westbound, but no agricultural inspection station. Yet the signage eastbound makes it seem like they are two separate weigh stations, so I'm not too sure what's going on here. Last time I drove this stretch was about three months ago, but my memory is cloudy.

Anyway, I know the OP isn't driving through Florida, but it's helpful to know if there are states that do require rental trucks to enter weigh stations, and to know if states have any specific requirements for carrying CDLs.

You sure there is no ah check westbound? I thought we checked both going in and out of the state. Unlicensed citrus exports are a big concern due to citrus canker so I assumed that was one of the motivating factors for ag checks opoutbound.

[Ace10]

You sure there is no ah check westbound? I thought we checked both going in and out of the state. Unlicensed citrus exports are a big concern due to citrus canker so I assumed that was one of the motivating factors for ag checks opoutbound.

I couldn't remember seeing one going westbound on my previous trips, so I checked Google Street View, and there is no signage regarding an agricultural checkpoint/inspection station. I checked from Exit 5 (US 90 Alternate) to the weigh station itself.

NE2 mentioned that "all paved routes into the Florida peninsula pass one", so perhaps there is another one further east that would check for westbound traffic. Are there lots of citrus growers in the panhandle? Florida may not be worried about panhandle traffic, but would more likely catch traffic coming out of the peninsula further upstream.

[NE2]

Yep, the one on I-10 near Pensacola is an exception. All other ag checkpoints are two-way at the peninsula entrances.

(quickie on MapQuest OSM background)

[Alps]

Yep, the one on I-10 near Pensacola is an exception. All other ag checkpoints are two-way at the peninsula entrances.

(quickie on MapQuest OSM background)

This seems to leave plenty of holes on smaller roads. So the trick to smuggling citrus is to be a roadgeek.

[NE2]

This seems to leave plenty of holes on smaller roads. So the trick to smuggling citrus is to be a roadgeek.

Nope - those are the only crossings of the Suwannee and St. Marys Rivers, except for one (CR 120) with a 3 ton weight limit and another (Stokes Road) with unpaved approaches. There are some unpaved roads crossing the cordon between the two rivers, and the checkpoint on US 1 is far enough south that you can turn off onto CR 121.

So the only hole that's reasonable for trucks is CR 121 west of Hilliard (or Lake Hampton/Murrhee to the east).

[edit] added the rivers, except the upper St. Marys because I suck:

The northernmost checkpoint on the Suwannee is actually on US 441 south of CR 6. The northernmost on the St. Marys also serves SR 2 traffic turning south on CR 127. There are no paved roads between the two.