To find the total number of treats sold by the ice cream truck driver, you need to add the number of Popsicles sold to the number of ice creams sold.
The calculation is as follows:
\[ 50,778 \text{ (Popsicles)} + 5,474 \text{ (ice creams)} = 56,252 \text{ (total treats)} \]
Thus, the driver sold a total of 56,252 treats.