I have my school aged Simmies walk to school when they live nearby. Those who live further away bike to school (I have the school bus disabled). I try to time it so they get there near the tail-end of the line. By that time, there are so few Sim children waiting to get into school, that the routing is a bit faster. Most times it's about 9:30 when they are finally able to actually walk through the door. On the days when I absolutely want them to be first or near first in line, I have them wake by 5am, eat a good breakfast and leave by 7:30am