As a comparison, I planted some of the identical plants in containers in the old spot so I could directly measure the differences. I installed automated watering for both, attempting to apply similar water in both locations.
The control plants were:
Texas Sweet Onions
Curly leaf Parsley
Observations as of mid-July
Early in the season, the driveway garden won hands down. The driveway garden receives twice the sun of the sideyard garden, and it was evident in early tomato production. The strawberries and Texas Sweet Onions also did much better, the onions producing fully formed onions sooner, and the strawberries thrived where in previous years they bore poorly in the sideyard.
However, as of today, the sideyard garden is producing good tomatos, cucumbers, parsley, and basil, while all plants except the strawberries, peppers, and basil in the driveway garden are showing extreme heat stress. More water isn't noticeably helping.
I'm thinking of changing the experiment in the fall. The driveway container garden sits on a white concrete driveway, and is on the East side of a 6 foot brick wall. It gets sun from about 2 hours after sunrise until about Noon, and then becomes sheltered from direct sun after that. I'm thinking the combination of the direct sun, the collection and reflection of heat by both the brick wall and the concrete may just be too much.
My plan is to move the container garden to the center of the driveway, forming a single mine down the center with a lane for a car on each side. This would provide for more sun, more air circulation, and less accumulated heat from the brick wall.
This past year, I planted winter lettuce in the sideyard garden. My observation is that it really didn't do well until late winter, when the lettuce produced quite well until about mid May. My hope is that the center driveway location will provide more sun for lettuce growth during mid-winter.
I'll report again next Spring on the results of the next experiment.