Q. Who makes the decision to close or delay? Usually it is the superintendent of a district. They usually confer with one or more of the following people: bus garage, police, road crews, other local superintendents.
Q. Is there a magic temperature when schools must close or delay? No. But many things are taken into account such as what kind of bus garage you have and what kind of fuel your buses use. If the buses are kept outside and use diesel fuel, the fuel turns to gel at around -4. Capability and man power of each garage to warm the vehicles and get them de-iced varies, so that is a major factor. You also have to look at bus runs. If there are buses that go many miles to pick up students there is a greater possibility the kids will be left standing outside for extended periods, subjecting children to the cold. On Monday I had a chid come to school with no coat. You also have to think about those parents who don't dress their kids appropriately or the fact that even little ones sometimes get themselves off to the bus each day, esp. when there is a delay.
Q. The roads don't seem that bad so why the delay/cancellation? Keep in mind that many districts like EF are between 26-45 sq. miles. In other parts of the state the districts are over 100 sq. miles. Your roads may look fine, but there are rural roads in other parts of the district where plows or salt trucks cannot reach to make a safe way for the bus. Also later in the season municipalities may run out of salt or non-skid.