ROSS DANGEL got angry, and his anger helped trigger a political coup this fall in Carroll County - one toppling pro-growth candidates and underscoring that the only viable option for Maryland is managed growth.

Three years ago, the insurance salesman moved to the patchwork of developments that have cropped up around the intersection of routes 32 and 26 in Eldersburg, ground zero for Carroll's growth explosion. His commutes to Baltimore and Washington would be just 15 minutes longer, he figured, and he'd save $100,000 off a comparable home in closer-in Howard County.

But within a year, that calculus broke down as his time trapped in slow lines of traffic stretched and stretched. He and half the commuters on his block now work at home as much as possible. "My God," he says. "What are they doing to this place?"

It's simple: Carroll's commissioners cut a Faustian deal with developers, who ensnared the county in an addictive spiral of allowing more new homes to raise tax revenues to keep up with the rising demands of all the new residents. The result: the most imbalanced tax structure in the Baltimore region, 88 percent based on residential development - unsustainable because homes often cost more in services than their owners pay in taxes.

To be sure, Carroll made some far-sighted choices. It's a national leader in land preservation. Its agricultural zoning is comparatively strong. And 30 years ago, it opted to channel growth around its eight small towns and to its unincorporated southeast corner near the Liberty Reservoir, aptly named the Freedom Election District.

But then no one minded the store.

No one kept good track of how many residential lots were being allowed, in growth areas or outside. Carroll didn't consult with its towns about developments approved on their edges - or even with its own school system. Building permits were issued without sufficient infrastructure. With growing water shortages, there's even been talk of tapping Piney Run Lake, the heart of the county's largest park.

And in recent years, all this took place as Carroll's commissioners rallied around the causes of property rights and local control, proudly warring against outgoing Gov. Parris N. Glendening's Smart Growth efforts.

Not surprisingly, Carroll was among Maryland's boomtowns in the 1990s, growing three times faster than the Baltimore region as a whole. The Freedom area alone grew by 34 percent. Moreover, the county has so many potential lots outside its growth areas that they're projected to add up to more than a third of all such rural land developed in the entire Baltimore region over the next 20 years.

This is ex-urban Maryland: A tide of new residents, often fleeing older neighborhoods inside and along the state's two beltways, has been flooding into rural places as disparate as Harford, Frederick, Queen Anne's and Calvert counties, the newcomers' ever bigger lots eating land by as much as five times the rate of population growth. From 1982 to 1997, the developed areas of the Baltimore and Washington regions increased by 32 percent and 47 percent, respectively.

But in Carroll this fall, voters - prodded by such activists as the Freedom Area Citizens' Council, headed by Mr. Dangel - finally took a stand, rejecting longtime growth advocates running for county commissioner. A new commission now vows to limit residential construction and work closely with its towns. "People's eyes have opened," Mr. Dangel says. The only option is managed growth.

Across Maryland, this is increasingly evident: in Howard County, where final build-out fast approaches after the county grew by 32 percent in the 1990s; in Frederick, where water shortages forced the city and county to restrict building; in Harford, where there's been talk of making builders pay new impact fees or excise taxes; in Queen Anne's and Talbot counties, where slow-growth candidates swept incumbents this fall. Even the Home Builders Association of Maryland, once at odds with Smart Growth, now aggressively lobbies for more effective growth management.

A million residents will be added to Maryland over the next 20 years. Where will they live? What will that mean for everyone else?

Uncontrolled growth is no longer an option. There's not enough money to solve the problem solely by preserving land. Growth moratoriums alone can lead to more sprawl. As southern Carroll shuts down, for example, development leapfrogs to Pennsylvania. Washington workers, priced out of Montgomery County and now closed out of Frederick, jump to more distant Washington County, where permits for frame homes surged 36 percent last fiscal year.

But wait - Washington County just banned any more rural development for up to a year. Hello, West Virginia.

If Smart Growth is a tarnished label, give it another name, but now's the time to even more aggressively channel Maryland's growth into new patterns of development.

Tomorrow: Density