In less than a year as Maryland Transportation secretary, Lowell K. Bridwell has earned a reputation as a can-do administrator -- paving roads, fixing potholes, installing stoplights, visiting city councils and trekking through snowstorms to inspect highways and bridges in need of repair.

As point man for Gov. Harry Hughes on some of the governor's most delicate legislation, Bridwell, unlike his predecessor, has been eager to stroke legislators who for years feuded openly with the state's transportation department.

Bridwell is a valuable asset in the Hughes administration, particularly during this election year, drawing praise from politicians for his energetic pursuits around the state: He inspected a bridge in Del. Richard A. Palumbo's district; met for hours with the mayor of Gaithersburg to discuss transportation needs in Del. Mary Boerger's district, and provided $4 million of asphalt and stoplights for roads and intersections in Del. Gerard A. Devlin's district in Prince George's County.

Devlin, Boergers and Palumbo are all members of the powerful House of Delegates' Ways and Means Committee. They provided key votes last winter in favor of Hughes' controversial gasoline tax.

Beyond perfecting his image as the governor's most politically adroit cabinet member, another less glowing, even embarrassing, portrait has emerged. In June, a U.S. judge in New York accused Bridwell of "collusion" with New York officials for his role between 1972 and 1981 as project manager of Westway in Manhattan, one of the nation's most expensive and controversial road projects.

Judge Thomas P. Griesa, in a June 30 opinion that blocked further federal funding of Westway, said Bridwell displayed "a striking lack of plausibility" during two days of court testimony and had "not disclosed facts in a full and candid fashion."

The 57-year-old Bridwell, a former federal highway administrator, showed "a remarkable amount of inconsistency, evasion, and asserted loss of memory on matters where memory would be expected," Griesa stated.

According to the judge, Bridwell, who was head of a consulting firm hired by New York to direct the Westway project, acted unethically in withholding key environmental data from the U.S. Army Corps of Engineers that could have jeopardized a Westway landfill in the Hudson River.

A New York lawyer familiar with the Westway controversy, who knows and admires Bridwell, said Bridwell "really has been unscrupulous here and he should be held accountable. They Bridwell and New York officials just tried to finesse it and they ended up misrepresenting the facts ."

Such accusations present a harsh contrast to the praise heaped on Bridwell in Maryland political quarters. And they draw unflattering attention to the "clean government" administration of Hughes, who came to office in 1978 promising to end corruption in the statehouse after years of scandals involving former governors Marvin Mandel and Spiro Agnew.

So far, Hughes administration officials have been silent on Westway, preferring to label it, as Bridwell did recently, "a New York case."

The governor, in his only public comment on the matter, said, "I know nothing about the Westway case, but I have known Lowell Bridwell for many years and have always known him to be trustworthy and of the highest integrity."

Bridwell, concerned by what he felt were incorrect news accounts in the New York and Baltimore media -- and also, according to a top Hughes aide, because a state Senate candidate was preparing "to make political hay" out of Westway -- asked the governor last month to appoint a three-member panel to conduct "an independent inquiry."

"Obviously it the press reports raised a cloud," Bridwell said the other day. "I wanted to clear it up as fast as possible. I will stand by the results of the inquiry."

The panelists, Attorney General Stephen H. Sachs, House Speaker Benjamin L. Cardin (D-Baltimore), and Anne Arundel County Republican Sen. John A. Cade, have no specific deadline, and all three will be campaigning for reelection this fall. While the inquiry is under way, Hughes said he will make no further comments about Bridwell or Westway.

For his part, Bridwell has maintained that the New York judge "misinterpreted" his actions. "There was no collusion, no covering up. All of the information generated in the environmental impact study was made public. I wrote to the Corps of Engineers saying I was withholding some raw data in the study , and why, and when I would make it available. I did make it available at the time I said I would." Bridwell said he was merely carrying out instructions from the New York transportation department's counsel.

Within Maryland's state government, Bridwell's New York problems have aroused little concern. A spokesman for Attorney General Sachs would not comment, explaining that the department is "playing it close to the vest" until the inquiry is finished. At state DOT headquarters at Baltimore-Washington International Airport, one official said, "I haven't been worried. I haven't heard any negative comments. He hasn't had any problems."

Many state officials and politicians continue to perceive Bridwell through his bountiful personal charm and patience -- he was a familiar sight in Annapolis last winter, darting from office to office in the House and Senate to review charts and figures with legislators -- and through his well-known accomplishments as the man who spearheaded development of a national transportation agency and designed the progressive Maryland department 11 years ago.

They remember him as a newspaper reporter who for a decade covered federal transportation and whose extensive knowledge of roads, highways, bridges and railroads led him ultimately to become the federal highway administrator. And they have all heard the familiar tale that, as a behind-the-scenes architect of Maryland's department, Bridwell told then-governor Mandel that there was "only one man" to preside as the state's first transportation secretary: Harry Hughes.

More important now for Democratic candidate Hughes than Bridwell's reputation for knowing roads is that his New York activities scarcely have blemished the gubernatorial campaign, even as the Sept. 14 primary approaches.

If there is a lone voice piping up to criticize Bridwell, it is that of influential State Sen. Harry J. McGuirk, a Baltimore Democrat running against Hughes in the primary.

McGuirk has called on Hughes to appoint a special prosecutor to investigate Bridwell, saying the panel of Sachs, Cardin and Cade could not be expected to conduct an investigation while each is running for reelection.

With Bridwell as the focus, McGuirk has attacked Hughes on a series of transportation issues. Last winter he crusaded against Hughes' auto emissions inspection program, an issue the governor quickly defused.

McGuirk's closest political ally, Del. Paul Weisengoff (D-Baltimore), a member of the Ways and Means Committee, spent hours last session trying to sway the committee against Hughes' gasoline tax. "It was one of the few times in years," one committee member remembered, "that Weisengoff was beaten on that committee. And Lowell Bridwell did it."

McGuirk stalled Bridwell's nomination hearings during the General Assembly session to investigate contracts that his old consulting firm, System Design Concepts, had in Maryland during the past decade. McGuirk and Weisengoff contend that Bridwell failed during those hearings to report any contracts his firm held with the state after 1974, an error Weisengoff says "warrants his being removed from office."

Although there are no transcripts of the hearings, Bridwell sent a letter to Senate Executive Nominations Committee Chairman Sen. Margaret C. Schweinhaut (D-Montgomery) that said no contracts were initiated after 1974. The discrepancy alleged by Weisengoff is contained in a state audit that shows that in 1976 the state extended an existing contract with Bridwell's firm for additional services costing $67,000. The contract expired in 1981, before Bridwell took office.

Bridwell, who provided documentation of his contracts to the committee after the hearings, said the records "substantiate my oral testimony."

So far, McGuirk's criticisms of Bridwell have failed to generate much response from the press or public, partly because he has confined his attacks to speeches in front of small, local groups such as the South Arundel Democratic Association. He repeatedly has promised to raise the issue in the final month of the campaign unless the state inquiry is completed before then, and on Wednesday sent a hand-delivered letter to Hughes reminding him of his call for a special prosecutor.

"This is not the type of thing that is aimed directly at the governor," McGuirk said last week. "It is the whole package. The legislature has been very much concerned in the last three or four years about the transportation department, about bad figures, bad inventories, loss of 13,000 special permits, and the awarding of bids to one or two firms.

"Bridwell comes in and by conversation promises to clean it up and do all of these things, only to be followed by a federal judge chastising him for withholding information," McGuirk added. "Withholding information doesn't bother his conscience one bit. The thing we are trying to clear up is exactly what he is accused of doing by a federal judge."

To McGuirk's chagrin, many legislators who grew to appreciate Bridwell during the General Assembly session last winter and who welcomed his accessibility, are reluctant to criticize him now.

"I think we're lucky to have a guy who can spend money wisely in the 23rd District," said Devlin, referring bluntly to $4 million in road projects his Bowie district has received since passage of the gasoline tax. " . . . Great projects have been held up because of snail darters and louse warts. He has changed that."