The opening of three bridges that are part of Virginia's Springfield interchange reconstruction will be delayed several months, raising the likelihood that the costly and complex project won't be completed by the summer of 2007 as scheduled, state transportation officials said.

Officials are so worried about the pace of construction that they are requiring the project's primary builder, Archer Western Contractors Ltd., to detail a plan by Friday for how the company expects to get back on schedule.

"At the rate they're going, I don't see them completing the project on time," said Dennis C. Morrison, Northern Virginia administrator for the Virginia Department of Transportation.

Larry Cloyed, VDOT's project manager at Springfield, said most of the problems were related to poor management at Archer Western. "If the plan is not where the plan needs to be, the state will have to consider the necessary action available to it, which could potentially include a new contractor," he said.

That could add several more months to the completion time of the long-awaited highway improvements. But the completion date already is in jeopardy, the transportation officials said, because the slowdowns on the precisely timed construction program have a domino effect on other parts of the project.

Employees at the Springfield and Virginia offices of Archer Western declined to comment. A message left with the company's president was not returned.

The reconstruction of the interchange, an intricate and dangerous mix of freeway merges known as the Mixing Bowl, began in 1999. At $673 million, it is the second-costliest highway project underway in the Washington region after the rebuilding of the Woodrow Wilson Bridge.

The bowl contains a constantly boiling soup of accelerating and decelerating cars on Interstate 95, I-395 and the Capital Beltway. The reconstruction plan intends to make the interchange safer and more efficient, giving each direction of each highway its own ramp and creating a web of more than 30 ramps and 50 bridges.

The first major piece of the Springfield project, a ramp linking the Beltway's inner loop to I-95 south, opened in May 2004 and provided immediate relief to motorists by separating one element from that dangerous mix. Other ramps and bridges are designed to provide similar benefits.

Two bridges -- one connecting the southbound lanes of I-395 to the outer loop of the Beltway and another that will carry traffic from southbound I-395 and the inner loop to Route 644 (Old Keene Mill Road-Franconia Road) -- were scheduled to open this month, but that target has been pushed back to November at the earliest.

"The current estimate is that we're roughly about four months behind schedule for both of those bridges," Cloyed said.

A third bridge, which will link the northbound lanes of I-95 to the outer loop, was scheduled to open in October but likely won't be done until spring at the earliest, he said.

The delays are the latest setback for a project beset with problems from its beginning. The cost of the reconstruction originally was estimated at $220 million, but the price rose when state planners broadened its scope to include several local connections. Nonetheless, a federal review in 2002 found that most of the ballooning costs were the result of poor management and an inability to properly price aspects of the project.

VDOT officials detailed their concerns about Archer Western in a June 24 letter to the company. The letter stated that some delays were linked to rising steel prices but that most problems were caused by lax management. For instance, the company's project manager resigned in April, and a full-time replacement has not been found.

Under the administration of Gov. Mark R. Warner (D), VDOT's leaders have spent the past three years trying to regain the public's trust after years of delivering projects late and over budget, if at all. Since 2001, the agency has gone from delivering 20 percent of projects on time to 74 percent. On-budget performance has increased from 51 to 81 percent.

Transportation planners suffered other blows last month. The estimated cost of a proposed Metrorail line to Tysons Corner rose 60 percent to $2.4 billion. Meanwhile, a deal with a private developer to build a long-sought highway through southwestern Virginia hit a snag. State officials continue to be plagued by problems with transportation projects in the Hampton Roads area.

"I think they really do need to get their act together," said Del. Leo C. Wardrup Jr. (R-Virginia Beach), chairman of the House Transportation Committee. He said the problems at Springfield were linked to "too ambitious planning and too ambitious bidding."

Cloyed said that "with some two years left in the contract, we could potentially recover some of this lost time. But it'd be tough. It would really be tough."

The delays will increase the project's price tag, he said. Whatever the overruns turn out to be, Cloyed said, he expects them to be covered by the builder.

Interim VDOT Commissioner Gregory A. Whirley agreed that Archer Western is liable for overruns but acknowledged that he's "pretty certain there would be some differences of opinion" from the company about who is responsible for the delays. If VDOT is found responsible, the state would have to foot the bill.

The state's online database that tracks the progress and budgets of construction projects shows an overrun at Springfield of more than $3 million. It also shows that 33.9 percent of the work needed to complete the final phases of project has been done, while schedules called for 44 percent to be done at this point.

Work continues on a bridge from Interstate 395 south to the Beltway's outer loop, top, and a bridge between northbound Interstate 95 and the outer loop.