A branch that clears your car may still obstruct a delivery van or recreational vehicle. Before asking for lower branches to be removed, define the access you need rather than choosing an arbitrary pruning height.
Start with the vehicles and their route
List the vehicles that regularly use the driveway, including roof racks or other fixed equipment. Obtain dimensions from reliable vehicle information rather than driving underneath branches to test the fit.
Show the contractor where vehicles enter, turn, and park. Slopes and changes in driveway level affect the space between a vehicle and the canopy. Clearance along the route matters more than a measurement at one convenient spot.
Distinguish private access from required clearance
There is no single clearance height suitable for every driveway and tree. If the route also serves emergency access or crosses a public sidewalk or roadway, confirm applicable requirements with the responsible local authority. Do not assume a height found online applies to your San Diego property.
Allow for a living, moving canopy
Branches move and grow, so a barely adequate gap today may not remain adequate. Ask the contractor what practical allowance is appropriate for the species, branch structure, and use of the driveway. Avoid requesting excessive removal simply to postpone all future maintenance.
Match the target to what the tree can tolerate
A desired height is a planning goal, not permission to remove every branch below it. Large low limbs, tree condition, and the amount of remaining foliage can limit what is appropriate. A different parking position or delivery route may be preferable if the requested clearance would require damaging cuts.
When discussing crown raising for driveway clearance, bring vehicle dimensions and a simple route sketch. Ask for the agreed clearance area and any limitations in the written scope so the finished work addresses access without unnecessarily stripping the canopy.