In the heart of this Eastern Shore county seat, bells still peal in the clock tower, interrupted sometimes by the siren at the Goodwill Volunteer Fire Department. Stately Victorians line the streets surrounding the 200-year-old courthouse. Parking meters take nickels.

But drive a mile in either direction, and the town looks squeezed, hemmed in by new housing developments that have caused the population to swell by several hundred people, to 2,600. The two-lane highway through town, Route 213, carries bumper-to-bumper traffic at times. Down the road from Draper's, a store that sells shotgun shells as well as the best subs in town, local teenagers attend a high school that's running out of room for them.

After decades of standing still, Centreville is morphing from rural hamlet into outlying suburb. It was one of the first Eastern Shore towns to struggle with the pressures that come with growth, but it is no longer exceptional.

More than 50 years after a ceremonial caravan of dignitaries opened the Bay Bridge, ushering in a first wave of growth here, a second - much bigger - wave is coming.

Nearly every farming and fishing village on the Shore is considering some sort of residential development. Planners are predicting a 25-year surge that is expected to boost the Maryland Shore's population by nearly a third, adding 160,000 new residents to 425,000 already here.

Baby boomers are flocking to the Lower Shore, snapping up everything from rural retreats to waterfront condos as second or retirement homes. Commuters, undaunted by increasing traffic, are settling in towns that, like Centreville, are prized as much for access to U.S. 50 as for rural ambience. Developers are marketing these places as the "commutable shore," with real estate agents pointing to their proximity to Annapolis, Wilmington, Del., or even Baltimore, which is at least 75 minutes away.

Supporters say such development can bring vitality to towns that for years were hemorrhaging population.

"If you have gone from 12,500 people in 1960 to 11,000 residents today, I would stipulate you would require some kind of stimulus," says Cambridge Mayor Cleveland L. Rippons. "How can you say we're growing too fast when you see that population loss?"

But an influx of people can bring traffic congestion, crowded schools, cluttered landscapes and something less tangible - a loss of charm in a region dear to many Marylanders. More and more, both longtime residents and newcomers are joining environmentalists in asking whether anyone has a plan to handle the onslaught.

"There is endless, endless growth, and there's no one looking at the cumulative effect of each of those projects on the resources of the region," says Dru Schmidt-Perkins, executive director of the environmental group 1000 Friends of Maryland. "That should be where the state is stepping in and saying very clearly, 'We're not going to bail you out here and pay for an 18-lane [U.S.] 50 to meet those needs.'"

Several million people live in metropolitan areas near the Eastern Shore, and many of them are looking for somewhere to move where they can actually afford a house with a yard. The growth is all over the Shore, including places planners have least expected to see it.

Mayor Rippons' Cambridge is expecting about 6,600 new houses and condos - many of them virtually on the edge of the Blackwater National Wildlife Refuge. In Chestertown, home to 4,700 people as well as Washington College, civic leaders once railed against development. Now, they are considering two annexation proposals that would bring nearly 1,000 new households.

But much of the growth is coming to tiny towns. Their frustrated residents want a grocery store or a sewage treatment plant, and they are happy to have a developer build one for them - even if that means doubling or tripling the size of their community.

No single government office keeps track of all these plans. A survey by The Sun of more than two dozen towns across the Shore found that they together are considering proposals for at least 25,000 new homes. Among them:

• Residents of Snow Hill, population 2,409, voted in March to annex 1,000 acres of farmland to their Pocomoke River town. Plans call for more than 2,000 homes to be built on former corn and soybean fields.

• Twelve miles from Denton in Caroline County, Goldsboro's 200 residents are waiting for crews to break ground on 500 new homes aimed at commuters who work in Delaware or Anne Arundel County. Many of the town's septic systems are failing, and the developer has offered to build a sewage treatment plant.

• Trappe, a cluster of about 400 homes along busy U.S. 50, has endorsed plans to build 3,000 more during the next 20 years. The new tax revenue could pay for a town police force.

• On the Kent County-Queen Anne's border, little Millington has a bank, a hardware store, a pub, a grocery store and a pharmacy. Now, a developer wants the town of 450 to annex a farm outside its borders and let him build 600 houses.

• Hebron, a lower-Shore town of about 800 residents, has become a bedroom community for fast-growing Salisbury. Hebron is planning for several hundred new homes during the next two decades, a figure that could double its population.