We utilize the Propeller/Trimble Stratus PPK solution (Phantom 4 RTK drone) and are very happy (8.5/10) with the service and accuracy provided. We’ve surveyed several hundred acre sites, sometimes more than one site a day, with a one man crew / pilot many times. Usually (but not always), Propeller turns the processing around in under 24 hrs.
Propeller has multiple tools for progress tracking or you can download the data for further use in TBC.
Good morning @Andy_Deveney,
The flight, for the AMG spec requirements we’ll be using traditional methods to provide that data.
For the flight our Caltrans RE refers us to the Division of Aeronautics and the Division of Aeronautics refers us back to Caltrans. I’m stuck in a infinite bureaucratic loop. I’ll be doing more digging this week, just seeing if know what Caltrans wants/requires in order to get or drone in the air.
Good morning Jason,
Differ to the FAA, which controls the airspace, to begin with.
Have a part 107? 
Have all relevant waivers?
I have never had an RE issue flying with Caltrans as the only restrictions they can enforce is encroachment, and only if taking off or land on their property. Assuming the project already has an encroachment permit, they cannot stop one from flying a site if the drone flights are clear with the FAA.
Generally, there will be no issue if the flight is for survey or engineering work on the project. However, it sounds like the RE needs to be educated.
It is prudent to hold all necessary waivers. 107.39 is a major one and is difficult to obtain. With proper FAA guidance and authorizations, you will be good to go.
The link below is to the Caltrans UAS section, which will send you to encroachment requests.