These people have obviously never seen a Habitat for Humanity development, or talked to anyone who owns a Habitat home, and they very likely don't even have a basic knowledge of what Habitat does. They just hear "low-income housing," know they don't want those people in their posh neighborhood, and come up with the traffic excuse to explain their opposition.
Habitat is perhaps the most well-run non-profit I've become acquainted with. The homes are high-quality, the owners are chosen with great care, and safeguards are put in place to make sure the families who live there are stable. Anyone would be lucky to have a Habitat home in their neighborhood.