"Simpson's paradox, which also goes by several other names, is a phenomenon in probability and statistics in which a trend appears in several groups of data but disappears or reverses when the groups are combined. "

In this case, the effect when the data is separated out is that AP is only marginally safer. When they are combined, it appears to be significantly safer.

I'd say this isn't a case of simpsons paradox at all.

It's more traditional sampling bias than Simpsons paradox

The performance appears to be superior due to a large proportion of the driving is done on easy environment.

The groups aren’t segmented by freeway vs. non-freeway use, but it’s an important omitted lurking variable. After conditioning on the variable, the takeaway changes.