Congressional leaders moved closer to agreement on a deal to avoid a doubling of the interest rate on certain need-based federal student loans, the Associated Press reported. The measure will be combined with a highway-projects bill, and lawmakers hope to get final approval this week. The student-loan deal, announced by the Senate’s majority and minority leaders on Tuesday, would extend for one year a 3.4-percent interest rate on newly issued subsidized Stafford loans to undergraduates. The rate is scheduled to rise to 6.8 percent on Sunday. There had been concern whether House Republicans would sign on to the Senate leaders’ plan, but the speaker of the House, Rep. John Boehner of Ohio, said after meeting with other Republican leaders on Wednesday, “We’re moving, I think, towards an agreement.” The deal does not affect other types of student loans, including those for graduate students, which will become more expensive after Sunday.