ASSOCIATED PRESS

CLARKSBURG, W.Va. — Booming production of oil and natural gas has exacted a little-known price on some of the nation’s roads, contributing to a spike in traffic fatalities in states where many streets and highways are choked with large trucks and heavy drilling equipment.

An Associated Press analysis of traffic deaths and U.S. census data in six drilling states shows that in some places, fatalities have more than quadrupled since 2004 — a period when most American roads have become much safer even as the population has grown.

The industry acknowledges the problem, and traffic agencies and oil companies say they are taking steps to improve safety. But no one imagines that the risks will be eliminated quickly or easily.

The energy boom, fueled largely by new drilling technology, has created badly needed jobs, lifted local economies and drawn global manufacturers back to the United States. But the frenzy of drilling activity contributes heavily to the flood of traffic of all kinds that experts say has led to the increase in serious accidents and deaths.

Not all of the crashes involved trucks from drilling projects, and the accidents have been blamed on both ordinary motorists and heavy-equipment drivers.

In North Dakota drilling counties, the population has soared 43 percent over the last decade, while traffic fatalities increased 350 percent, to 63 last year from 14 10 years ago. Roads in those counties were nearly twice as deadly per mile driven as the rest of the state.

Traffic fatalities in Pennsylvania drilling counties rose 4 percent over that time frame, while in the rest of the state they fell 19 percent.