Children eagerly took to sledding and making snowmen last week when a storm left several inches of snow, prompting two school-free days in Prince William County.

The county announced about 11 p.m. Tuesday that schools would be closed Wednesday and about 5 p.m. Wednesday that there would be no school on Thursday, either.

How does the county decide when to close schools because of the weather? Ed Bishop, who has been the director of transportation services for county schools for 11 years, is part of the team that gathers information and makes a recommendation to School Superintendent Steven L. Walts.

Here are edited excerpts from an interview with Bishop.

What makes them call it early, like this time?

“When we make the call early, it’s generally made 100 percent based on weather reports. When [Walts] believes a preponderance of the reports indicate we’re not going to have school, he likes to get the word out as soon as possible because he knows lots of families have to make arrangements for child care.”

Is it stressful to be the one making the call?

“It only takes one [accident]. Every child in this county is important to somebody. Parents are emotional about it, and they should be. . . . I used to love the winter, but after I got this job, it’s not as much fun as it used to be. There are frequently those times when you’re involved in these road surveys and providing input to the people making decisions. When you’re talking about the safety of 85,000 students, that’s a lot of pressure. I worry an awful lot about taking kids to school in the morning on clear roads and having to take them home on icy roads in the afternoon. You’ve got to think about what it’s going to be like at 1:30 this afternoon, because to have a busload of students on the side of an icy highway with 50-60 worried parents, it weighs on you a little bit.”

What are the biggest factors in the decision?

“Ninety-nine percent of the decision is about safety. Sometimes it’s about the ability to operate schools. When we drive around and do our check, we look at about 33 of the 94 schools in the county. We’re looking for power outages or plumbing problems, too.”

Do you consider employee commutes when you are deciding?

“We have 10,000 employees in the division who have to drive into work, and many of them come from outside of Prince William County. If the surrounding counties have had heavy snowfall and we haven’t, we have to consider the impact.”

Do you feel like people are unhappy no matter what decision you make?

“I would say it’s absolutely impossible to please 400,000 residents in Prince William County. It just isn’t possible to do. When we make a decision to open schools or to close schools, we’re thinking about the majority of the population that’s affected. We always tell parents that if your neighborhood is unsafe, if your children can’t walk to the bus stop safely or you can’t drive them safely, do not do so. It just isn’t possible for us to check every single road in Prince William County, and the roads vary from four-lane high speed highways to unimproved, barely two-lane roads that I refer to as ‘goat trails.’ ”

What do you look for when you go out on a run to make the call?

“We divide the county into five geographic areas, and myself and four other employees from the department are assigned to those areas. There are certain roads we know are problematic, so we hit those. We know we’re going to go by a number of schools, so we’re looking at the condition of sidewalks and driveways. Normally around most of our schools, in particular the elementary schools, there is a designated walk area that can extend up to one mile. We are looking to see how much snow is piled up at bus stops, are the sidewalks clear, can the little ones get to school if they are forced to walk.”

There was a big difference between the snowfall on the eastern end of the county than on the western end. Does that make it more difficult for people to understand?

“It’s the strangest phenomenon in the world. There was a period [a few] weeks ago where it was raining to beat the band in the early morning hours between Manassas and Route 1, but west of Manassas, right around 3:30 or 4 a.m., there was tremendous snowfall. By the time I got to Route 15 at 4:30 in the morning, it was a whiteout. Based on the forecast that it was going to warm up, we went with a two-hour delay. I’ve seen situations where the west side of the county is dry and clear, and the east side of the county was a sheet of ice. People always ask, if it’s clear on the east side, but not on the west side, why can’t you open schools on the east side.

It’s a logical question, but the truth is that many, many of our students do not attend schools located in their boundary areas. In particular with our specialty and special education programs, many of those students cross boundaries and, of course, we transport them. Some of those schools [serve half the county, some serve the whole county]. We’re really an integrated school division, so what do you do if you open on the east side of county, but you still have to transport students to and from the west side of county? You still have the same safety factor. . . . There are some instructional and educational impacts as well. If you get some schools that have more instructional hours than others, you don’t have a standardized exam schedule or graduation schedule. The academic staff likes to keep instructional days on a pretty even par across the county.”