Bicycling in the Maryland countryside is not always as simple and pleasant as it sounds.

For Larry Black of College Park and nine other cyclists who went for afternoon spins in Prince George's and Baltimore counties on New Year's Day, the holiday ended in arguments with police and three arrests for alleged violations of Maryland's rules of the road.

Their cases, soon to come up in courts in both jurisdictions, demonstrate the room for misinterpretation in Maryland's laws on bicycling -- laws that national traffic safety officials say are among the most restrictive and confusing in the nation.

"We were riding single file at the far right hand side of a country road on a clear afternoon with no traffic . . . and we were violating no laws," said Black, a College Park bicycle shop owner and president of the National Capital Velo Club, the nation's largest racing-oriented bike club. He has taught bicycling, including classes on safety and bike law, for eight years at the University of Maryland and for the Montgomery County Recreation Department.

A Maryland state trooper stopped Black and gave him a ticket for "failure to obey bicycle safety rules," Black said, because Black and a companion, Martha Rainey, on a tandem bike, and a friend, Jim Meiklejohn, on a second bike, were not riding on the shoulder of Rte. 197 near Bowie. Black said the shoulder was covered with glass, gravel and pot holes, and two dogs were running at large on it when the trooper stopped the group. The "drivers" of both bikes were ticketed.

Moments earlier, the same trooper had ordered Black and his friends off Rte. 3 and had given the bicyclists verbal warnings, telling them it was illegal to ride on that road at all because it has a 55 m.p.h. speed limit.

"The road has a 50 m.p.h. speed limit and we were riding on it legally," Black insists.

In the Baltimore case, Joseph G. Gardiner, an English professor and bicycle columnist for The Baltimore Sunday Sun, was arrested at about the same time New Year's Day as he led a bicycle club ride on a four-lane suburban road. Gardiner said his group was riding single file in the far righthand lane, although police later said the group was obstructing traffic and riding two abreast. Riding side by side, once illegal in Maryland, was made legal in 1979, so long as it does not impede traffic.

Because Gardiner refused to show a motor vehicle driver's license (although he offered other identification), he was taken to a police station and handcuffed to a water pipe for more than two hours while the arresting officer wrote his report, according to Gardiner and accounts in The Sun.

Gardiner was charged with impeding traffic, with "violation of restrictions regarding bicycles on a roadway," and with refusal to obey an officer -- allegedly, he and his group failed to stop immediately.

In a subsequent Sun story, the police officer claimed Gardiner had been "argumentative and uncooperative . . . all I wanted to do was get them (the bicyclists) to move over" next to the curb.

Maryland, like most states, follows the nation's model uniform traffic law on bicycles, which generally calls for bicyclists to ride as far to the right "as practicable."

Maryland, however, also requires that if there is a bike lane or shoulder that is "paved to a smooth surface," bicyclists must ride on it. Exceptions are moving onto the main roadway to make left turns, to pass or to avoid "debris or other hazardous conditions." Three months ago the state announced a definition of "smooth surface" to help cyclists interpret the law: a bicyclist must ride on the shoulder of a road if it has a "texture equal to or better than" the roadway and is no more "undulating." If it is bumpier than the road or filled with glass, gravel or potholes, cyclists may ride on the road.

Until two years ago, Maryland required bicyclists to ride on road shoulders and bike paths regardless of their condition.

Another Maryland restriction, unusual in most other states, bars cyclists from all 55 m.p.h. "roadways," as well as from all "controlled-access highways" such as interstates and parkways. There are hundreds of rural roads around the state, particularly on the Eastern Shore and in western Maryland, with 55 m.p.h. speed limits. Few if any have signs stating this prohibition and many local and out-of-state bicyclists have been stopped by police, according to Edward Kearney, executive director of the National Committee on Uniform Traffic Laws and Ordinances.

However, to add to the confusion, while bicyclists are banned totally from "controlled access highways" -- highway means the road and road shoulders -- they apparently can ride on the shoulders of other 55 m.p.h. roads.

Steven McHenry, Maryland's bicycle affairs coordinator for the transportation department, said "in some instances we've overregulated" the use of bicycles on public roads. But he insisted the state is attempting to clarify its laws, saying, "We've had amendments almost every year." He also said the restrictions were intended primarily to protect children and inexperienced bicyclists, and that police may be stopping bicyclists "thinking 'I'm going to save this man and get him off this terrible roadway.'"

Black and Meiklejohn are scheduled to appear in traffic court, the District Court of Maryland in Oxon Hill, on March 18. No court date has been set for Gardiner.

Maryland now publishes a 12-page pamphlet with verbatim excerpts from state bicycle laws. It is available free at Motor Vehicle Department offices, or by writing the Maryland Motor Vehicle Administration, 6601 Ritchie Highway NE, Glen Burnie, Md. 21062.