In the US and Canada, road transport makes up about a third of the footprint of the top 10%. The transport emissions of the richest 10% are the same as the transport footprint of the bottom 70% of the population in those countries.

This is probably dominated by the 1% as you mention. The bottom 70% combined certainly drives much more than the top 1%/10%, but just gets absolutely dwarfed by other transportation emissions (likely recreational air travel). Top 10% in the US is rich, but not private jets to go to dinner at the hot new spot in a different city rich.