Growing traffic is creating new headaches on the winding two-lane roads of Amish country in Charles County, where residents rely on horse-drawn carriages.

As motorists seek alternatives to crowded main thoroughfares, the following scenario is becoming more common: A dump truck rumbles at 50 mph on a back road that dips and bends its way past signs for cabinet craftsmen, mini-barn builders and plant nurseries. Up ahead, a horse clops along pulling a carriage in the opposite direction at 20 mph with two cars trailing.

What happens when the cars pull out to pass the carriage just as the truck turns a blind corner?

The answer, according to woodworker Benuel Yoder, is something like this: The truck swerves across the yellow line into the path of the carriage. With tires and brakes smoking, it comes to a stop just before reaching the buggy.

This type of close call "happens every weekend. It is a head-on waiting to happen," said Yoder, 43, who is part of the Amish community that straddles the Charles-St. Mary's border.

"Trucks are flying down through these country roads, and they forget there might be a buggy on the other side of the hill," he said.

It is also possible that drivers who are new to the fast-growing area do not know to look for them.

At Yoder's urging, Charles County is giving motorists a heads up. Workers have posted a half-dozen signs featuring a silhouette of a horse and buggy.

State highway officials have long marked major roads in the area, such as Route 5, where an Amish woman and her three children were injured in 2001 when a van collided with their horse-drawn buggy. St. Mary's County began alerting drivers to the slow-moving vehicles in the mid-1980s.

Until recently, Yoder's section of Charles near the St. Mary's County line seemed secluded. But in the past five years, he said, there has been a "right big change."

There are no official statistics on the number of accidents involving horse-drawn carriages. State highway officials and the Charles County Sheriff's Office do not have a separate category for buggies.

The change that Yoder and others describe has coincided with an increase of more than 13 percent in the county's population, to about 137,000.

The level of concern has also risen among the roughly 120 Amish families in the area because motor sports enthusiasts and competitors have started to use the back roads as a shortcut to the speedways in nearby Budds Creek.

On summer weekends, the motocross and stock car races draw thousands of vehicles, many hauling trailers. Bryan Starner, a spokesman for the Maryland International Raceway, said fans are advised to take major roads to the drag racing stadium, which holds 15,000 people.

"I wouldn't want to take a tractor-trailer on a winding road," he said. "I would prefer to do straight shots."

Most of the spectators traveling to the Potomac Speedway use major roads, spokeswoman Denise Hollidge said. But the speedway's Web site recommends a "scenic route" that takes drivers down Trinity Church Road, a well-traveled path for horse-drawn carriages.

Yoder asked motorists for patience when passing.

"You feel like a miniature," he said. "If a car hits a buggy, there's nothing left of the buggy. It's steel against toothpicks."

A buggy travels down Route 236 in Mechanicsville. Workers in Charles County have posted a half-dozen signs featuring a silhouette of a horse and buggy. This sign was installed on Ryceville Road. About 120 Amish families live in the area. Close calls with automobiles happen frequently, one man said.Woodworker Benuel Yoder said there has been a "right big change" in the amount of traffic on country roads near the Charles-St. Mary's line.