Four hours before dawn on the first day of 2012, a Chevrolet TrailBlazer going west on Jones Bridge Road in Bethesda struck a curb, crossed a sidewalk, hit a chain-link fence and slammed into a tree.

Two young adults — Nicholas S. Clayton, 20, and Kaitlin M. Gallagher, 18 — became the first two deaths in Maryland that year in a single-car crash, a type of accident that would claim 273 lives in the state before 2012 ended.

Although multicar pileups hold the imagination of most drivers when they picture a fatal accident, people are much more likely to die in a single-car crash, statistics show.

Over 2011 and 2012 in the District, Maryland and Virginia, 1,541 people died in single-car crashes. Those amounted to almost 60 percent of all traffic fatalities in those jurisdictions. Nationally, they make up an even higher number of all fatal crashes: about 65 percent, according to federal statistics.

Arguably, single-car accidents are within the driver’s ability to avoid, in most cases.

“We suspect they are the result of unbelted drivers who are speeding or perhaps drunk or distracted, or all three,” said Jonathan Adkins, deputy executive director of the Governors Highway Safety Association. “Unbelted drivers continue to be an issue in many states.”

John B. Townsend II of AAA Mid-Atlantic agrees with those risk factors but adds others: “drowsiness, inattentiveness and the over-correction of the vehicle, or, paradoxically, trying to avoid a crash.”

After six years of decline, the overall number of people killed on the nation’s roads increased in 2012, according to annual statistics released this year by the National Highway Traffic Safety Administration. Preliminary data for the first half of this year show a 4 percent decline from 2012.

Single-car crashes killed 157 people in the District and its commuting-distance communities in 2012.

“Single-vehicle crashes comprised nearly two-thirds of all traffic fatalities in Washington, D.C. proper, Maryland and Virginia combined from 2009 to 2011,” Townsend said. “Two-thirds of area commuters drive to work alone. Their most likely victims are themselves.”

This month’s victims included a 24-year-old police recruit who died after his vehicle struck a tree in Upper Marlboro, three family members whose car hit a tree off of Interstate 95 near Richmond, and a 54-year-old driver who was ejected from a vehicle after it hit a curb and overturned on the northbound side of Connecticut Avenue near Denfeld Avenue in Wheaton.

In October in Loudoun County, 26-year-old twins died near Evergreen Mills and Reservoir roads after a vehicle they were riding in crossed the center line, ran off the left side of the road, hit a tree and caught fire.

In July, the 49-year-old driver in a single-vehicle crash in the District died after striking a chain-link fence. In May, there were two other deaths in the District: Those of a 38-year-old driver who failed to negotiate a turn in the rain at Fifth and Harvard streets NW, and a 22-year-old whose car overturned while speeding on DC-295.

The Prince George’s County police department said a driver suffering from a medical emergency died in a crash in October near New Hampshire Avenue and Piney Branch Road.

Two Montgomery County drivers — one in Brookeville and the other in Laytonsville — died in September in a similar fashion: Their vehicles drifted off the road, struck trees and overturned.

A 22-year-old driver and two passengers were killed on Piney Orchard Parkway in May when their vehicle ran off the road, striking a light pole and two trees.