[quote Anonymous]I think it's time to get a chauffeur (that's what they are called) or maybe you could ask your butler in a pinch

Give OP a break. Transportation safety is hardly a trivial issue.
OP, double check the bus schedules for the commute. Many kids in our MS take metrobus because it's more reliable than metro. Drivers on our route keep an eye on the kids and know school staff. Circulator bus is good because of frequency.
A longer commute by bus might be worth saving the hassle of relying on the schedule of a sitter or older student who may not have a reliable backup.
Best of luck.