Maryland transportation officials released a study yesterday supporting their contention that a proposed highway linking Montgomery and Prince George's counties would add jobs, save travel time and protect businesses.

The east-west highway, known as the intercounty connector, would encourage the creation of nearly 17,000 jobs, according to the study commissioned by the Maryland State Highway Administration. Residents and businesses would save as much as $300 million a year, thanks to more efficient travel, the report said.

The highway's existence would encourage Maryland businesses to stay put, rather than look for better locations outside the state, and would support the growth of Baltimore-Washington International Airport, the study said.

It also concluded that more than 60 percent of the jobs created would be in the service and retail industries, and a small percentage would be of the high-paying type that business and civic leaders covet.

And it found that the "economic benefit of the ICC to regional carriers and shippers is likely to be only incremental." The time savings to a company such as FedEx, which has a sorting facility in Rockville, would be four to six minutes a day, enough to possibly add one delivery to the daily load.

The connector plan calls for construction of an 18-mile, toll highway linking the business corridor along Interstate 270 with Interstate 95, the main north-south artery on the East Coast and a direct link to BWI and the Port of Baltimore. The estimated cost of the six-lane road, which state officials hope to begin building in 2006, is $1.7 billion before financing charges.

Maryland politicians, business leaders and environmentalists have debated the highway plan for decades and the project lay dormant for several years until Gov. Robert L. Ehrlich (R) revived it after his election in 2002.

Backers of the idea saw the economic impact study as critical to solidifying support for it. State officials have dropped claims that the highway would reduce traffic congestion on the Capital Beltway or other major roads, though they say it would allow more people to use those roads as drivers shift to the connector.

The report found that the economic benefits for Prince George's were greater than for Montgomery, where most of the highway would be located, a result that state officials said answered questions about whether the highway would funnel jobs and business away from Prince George's.

"The benefits of the intercounty connector are widespread -- it's far more than a Montgomery County project," said Robert L. Flanagan, Maryland's transportation secretary. "It makes Prince George's County a more attractive place to have a business, and it creates encouragement for existing businesses to stay where they are."

The study looked at the impact of the two proposed routes of the highway from 2010 to 2030. State officials said the cost savings would be $6.7 billion over that period for one of the proposed routes, designated Corridor 1, and $5.7 billion for Corridor 2.

The savings would come mostly from reduced travel times, while vehicle operating costs, travel time reliability and improved freight traffic would account for some other savings.

Corridor 2 would generate 16,855 jobs, whereas Corridor 1 would create 14,200 jobs within five years of the highway's construction, the study said.

The connector's opponents say that it would lead to more suburban sprawl and that it would encourage development in a part of the state that is already crowded.

Many also fear that the road would divert economic development from Prince George's by giving people a direct link to I-270. They say that a better approach to improving mobility would be to add transit capacity, and that a better business development approach would be to encourage firms to locate at underutilized Metrorail stations in Prince George's.

Some opponents said the $300,000 study, part of a federal environmental review, was flawed because it compared the results of building the highway to only one alternative: not building it.

Opponents acknowledged that any new road capacity would improve short-term mobility and therefore lead to cost savings but said that focusing solely on that ignores the highway's impact on business development patterns over the long term.

Dru Schmidt-Perkins, executive director of 1000 Friends of Maryland, said the study missed the point. Instead of trying to figure out whether a single road would create jobs and lead to some savings, state leaders ought to be studying how to ease economic inequities in the region.

The study was done by a team at the University of Maryland, chosen as an independent party to allay concerns that the report would favor proponents of the connector.

But the manner in which the report was released nevertheless raised those very questions among opponents. Rather than releasing the findings at a news conference or other public venue, state highway officials met individually with a handful of reporters at the University of Maryland. State officials said they would not release approximately 800 pages of supporting documents for a few weeks.

"When the release is controlled by the secretary of transportation and the head of the State Highway Administration, it does call into question the independence" of those who did the study, said Stewart Schwartz, executive director of the Coalition for Smarter Growth. "It's certainly very difficult for the public and outside experts to evaluate the report without the supporting documentation."

State officials said they chose the one-on-one format because of the detailed nature of the report, and the study's director, Hani S. Mahmassani, said his group was not influenced by politics.

"We really did do this independently," Mahmassani said.