Washington (CNN) -- Distracted driving claimed the same percentage of overall traffic deaths in 2009 as in 2008, according to numbers released Monday, meaning it's still a big problem across the country, Transportation Secretary Ray LaHood says.
"These numbers show that distracted driving remains an epidemic in America, and they are just the tip of the iceberg," LaHood said.
The report from the National Highway Traffic Safety Administration shows crashes linked to distracted driving claimed 5,474 lives and led to 448,000 injuries across the United States in 2009. That amounts to 16 percent of the traffic fatalities in 2009, the same percentage as in 2008.
The proportion of fatalities associated with driver distraction has increased from 10 percent in 2005, the report says, and the greatest proportion of distracted drivers was in the under-20 age group.
A bright note in the report is that overall traffic fatalities fell in 2009 to their lowest levels since 1950.
The report was released one day before Lahood is scheduled to convene a National Distracted Driving Summit in Washington.
On Tuesday, leading transportation officials, safety advocates, law enforcement personnel, industry representatives, researchers and the family members of victims of distraction-related crashes will gather to address challenges and identify opportunities for national anti-distracted driving efforts, according to the Transportation Department.
In January, federal safety regulators proposed a set of guidelines for states to create laws that would ban text messaging while driving.
The proposed legislation, prepared by the traffic safety agency and industry advisers, would authorize law enforcement officers to stop a vehicle and issue a citation to drivers who are texting while driving.
"This language, which we created with a variety of safety organizations, is another powerful tool in our arsenal to help the states combat this serious threat," LaHood said.
Under the proposed guidelines, drivers caught typing on a handheld device while behind the wheel would face a minimum fine of $75 and unspecified action against their driving privileges. In cases resulting in serious injury or death, a driving while texting offense could be considered a felony.
A ban on texting behind the wheel has already been enacted in 19 states and the District of Columbia. Seven states have banned the use of all handheld devices while driving.
Regulators said texting is particularly dangerous because it distracts drivers in three ways: visually, manually and cognitively.
The sample state law is modeled on rules implemented last year directing federal employees not to engage in text messaging while driving government-owned vehicles or with government-owned equipment.
In addition, the Department of Transportation announced federal guidance earlier this year to prohibit texting by drivers of commercial vehicles such as large trucks and buses.
Truck and bus drivers who text while driving commercial vehicles may be subject to civil or criminal penalties of up to $2,750.
CNN'S Ben Rooney contributed to this report.