my comment, being mom of two sons, ( and not knowing the age of yours) is a) you can get in a lot of riding done inbetween pick up and drop off b) get in a rotating carpool so you get some time off c)they can walk or ride a bike to thier activity or home from school... you do not have to be there for everything or drive them everywhere.
I think taking them with you is great too... my 13 year old did 12 miles of mountain biking with 2000' of climbing with us yesterday.
Irulan.
2015 Liv Intrigue 2
Pro Mongoose Titanium Singlespeed
2012 Trek Madone 4.6 Compact SRAM