Washington ? The number of people killed in 2005 on U.S. roadways climbed to the highest level in 15 years, an increase tied to rising deaths among motorcyclists and pedestrians, the federal government reported Tuesday.

A total of 43,443 people died in traffic accidents last year, up 1.4 percent from the previous year, according to the National Highway Traffic Safety Administration.

The agency said the motorcycle death toll rose for the eighth straight year. Last year, 4,553 motorcyclists died on the roadways, up 13 percent from the previous year.

The agency also said 4,881 pedestrians were killed last year, up 4.4 percent.

“The traffic environment is getting more dangerous,” said Adrian Lund, president of the Insurance Institute for Highway Safety.

“People are driving a lot faster. We’ve lost momentum in reducing alcohol-impaired driving and unprotected road users, like pedestrians, and to some extent motorcyclists are going to suffer from that.”

Lund said state governments need to adopt stricter helmet laws. Twenty states have mandatory helmet laws for motorcyclists. Most recently, Pennsylvania, Florida and Texas have rolled back their helmet laws, according to a NHTSA spokesman.

According to NHTSA, states that have repealed helmet laws have seen sharp rises in motorcycle deaths. In Kansas, only motorcyclists younger than 18 are required by law to wear a helmet.

NHTSA said it has launched an investigation into the rising number of pedestrian deaths. The agency is providing $600 million over the next three years to help states develop safety programs for pedestrians.

Men are far more likely to die on the roads. In 2005, the number of men who died jumped 781 to 30,224, while female deaths declined 298 to 13,089. The number of bicyclists killed rose by 57 to 784.