First of all here is Austin it is now against the law to be talking on a cell phone when inside a school zone.
That mom could be ticketed for talking on her phone for even sitting in a running car inside a school zone. It has helped a lot.
Also in Austin, The streets where the kids are picked up and dropped off can only be in one direction.. No backing up is EVER allowed. so no backing into parking spots, instead the cars all have to move up. Also each child has to be picked up at the curb, so no walking between cars is allowed. We are also told to continue to move until you see your child and then you can stop, Parking is not allowed in the pick up lane.
We found that as kindergartners it helped a lot for them to learn the rules about dropping off and picking up. The kids could then remind their parents of the rules.
We used to have dads dressed like referees who had flags to get people to move. It was pretty funny.. They had whistles, striped shirts and caps..
We also gave the Principal "names of parents that we felt needed to be helpers" for morning or afternoon drop off.. It was pretty amazing how their driving became better after being put in charge of helping move that traffic.