The national president of Mothers Against Drunk Driving (MADD) has acknowledged that drugged driving is a growing problem but said alcohol-impaired driving remains the number one cause of roadway fatalities nationwide in recent testimony before the U.S. House Energy and Commerce Committee's Subcommittee on Digital Commerce and Consumer Protection.

Colleen Sheehey-Church, national president for MADD, highlighted research from the National Academy of Sciences and the Insurance Institute for Highway Safety that demonstrates alcohol is the greater threat and is responsible for more than 10,000 lost lives every year.

Several factors are linked to increased drug use, said Sheehey-Church. These include the legalization of medicinal and recreational marijuana in many states, the national opioid crisis and the growing use of prescription drugs.

However, she cautioned legislators from allowing provocative headlines to obscure the facts. Recent headlines stating that drugs have overtaken drunk driving in terms of generating more crash fatalities are false.

"The good news is that the best way to combat drug-impaired driving is to do more impaired driving enforcement," Sheehey-Church said.

MADD encouraged the Energy and Commerce Committee to work with law enforcement across the country to emphasize the importance of traffic enforcement.

In addition, the organization called for more police training through programs like Standardized Field Sobriety Checkpoints, Advanced Roadside Impairment Detection Enforcement, and the Drug Recognition Expert Program.

Finally, MADD recommended more research and data for drugged driving to help define and identify the impairing effects of legal and illegal drugs, and to better understand the number of drivers involved in drug-impaired driving crashes.

A recent report from the Government Highway Safety Association offers some insight into the link between drugged driving and roadway fatalities.

For example, in 2016, 43.6% of fatally injured drivers with known drug test results were drug-positive as compared with just 27.8% in 2006. Also, 41.1% of the drug-positive fatally injured drivers were positive for some form of marijuana.

While marijuana's effect on crash risk is not entirely clear, the best overall estimate in general is that it can increase crash risk by as much as 35%, according to the report.

Related: Will Autonomous Vehicles End Drunk Driving?