WARRENVILLE, Ill. — School bus contracting firm National Express Corp. held its fourth annual safety poster contest and received more than 230 submissions.

Employees from Durham School Services, Petermann and Stock Transportation participated in the company-wide contest, which celebrates safety in student transportation. The submissions were evaluated based on four categories: child check, pre/post-trip inspection, defensive driving and injury prevention.

Here are the winners, each of whom earned $1,000:

• Olga Reyes from Holyoke, Massachusetts, won first prize in the child check category for her “Don’t leave anyone behind” artwork.

• Lucy Wittenberg from Minnesota City, Minnesota, won first prize in the pre/post-trip category for her “Did you do your pre-trip?” poster.

• Stefan Mitev from Baltimore won first prize in the defensive driving category for his “Watch me?” artwork.

• Kathy Henderson from Richmond Hill, Ontario, won first prize in the injury prevention category for her “Seasonal safety awareness” poster.

“Safety is the top priority for all of our employees, and it is foremost in our minds as we do our jobs, every day,” said Michele McDermott, senior vice president of safety. “This poster contest highlights our commitment to safety throughout the organization. The poster submissions we received this year were amazing, and each demonstrated a different aspect of safety.”

Mansfield Oil, Bridgestone, Blue Bird and Seon sponsored this year’s safety poster contest.