OT: Kangaroos on Freeways
 

My mother saw one of those home video shows on TV and asked me to ask our Aussie friends if there is a big problem in Australia with Kangaroos congregating on freeways, or was that an isolated incident.

It's an isolated incident.
There are problems with kangaroos on roads but most of the time it's out in the countryside and typically it's a single 'roo or a small group attempting to cross from one side of the road to the other.

Naturally enough they become a traffic hazard but more often than not, because it's on a country road, there isn't much human traffic for the 'roos to worry about so they cross the roads relatively safely.

I'd rate the risk of encountering a kangaroo on the road about the same as encountering deer on the road in the USA - yes it happens often enough that the media doesn't bother reporting it most of the time but it doesn't happen often enough to be truly newsworthy.

Was I correct when I told my mother that a herd of kangaroos is actually called a "mob"?

Absolutely correct.