Prince William County high school students can look forward to fewer tests next year, as school officials have eliminated mandatory midterm exams.

The county’s high school principals unanimously signed on to a one-year pilot program that will free teachers from administering required semester exams in January and give them more time to prepare for end-of-year tests.

“Teachers do feel pressed for time,” said Michael A. Mulgrew, associate superintendent for high schools in Prince William. The combination of tougher academic standards and an overall emphasis on standardized testing “crowds out instructional time,” he said. “They want it back.”

Mulgrew announced the change at a School Board meeting last week. The pilot program did not require a board vote.

Semester exams, which account for 20 percent of a student’s grade, were introduced in Prince William in the 1970s as a way to offer students collegelike exams, Mulgrew told the board.

Now, students have a slew of standardized tests and multiple opportunities to take more rigorous tests, including some that can lead to college credit, such as Advanced Placement and International Baccalaureate exams.

Mulgrew said that semester — or midterm — exams monopolize more than two weeks of instructional time. Students this year began reviewing for their midterm exams as early as Jan. 17, and many did not learn new material until Feb. 4, he said.

The process was prolonged because of a snow day, a weather-related delay and a teacher workday. For three days, when exams were administered, students left before noon.

AP teachers in Virginia have long been concerned about an additional preparation crunch because of the state’s “Kings Dominion” law, which prohibits schools from starting classes before Labor Day each year. That means students in other states have longer to learn the material included on May exams.

School districts across the country are grappling with testing fatigue and searching for ways to dial back. But officials in most area school systems say that they still administer midterm exams. High failure rates on midterm math exams in Montgomery County this year raised concerns about the quality of instruction or the alignment of the tests.

The pilot program in Prince William will not affect next year’s end-of-year exams.

Jim Livingston, president of the Prince William Education Association, said teachers welcome the flexibility. Teachers can still give students an end-of-semester test if they choose to during their regular 90-minute class period, without having to block out separate exam days, he said.

“Teachers have been trying to make this point for a number of years,” he said. “The time could be better spent actually teaching, believe it or not.”