By Molly O'Toole
WASHINGTON (Reuters) - Distracted drivers are dangerous -- and difficult to study, according to a Governors Highway Safety Association (GHSA) report released on Thursday.
The report, assessing research from more than 350 scientific papers published since 2000, concluded that distractions do affect driving performance. Drivers are distracted up to half the time, primarily by cell phones and other electronic devices in the car.
Distractions are associated with 15 to 25 percent of crashes, from minor damage to fatal injury, according to the report. Cell phone use increases the risk of crashing, but texting is likely to increase crash risk more than cell phone use.
Yet the report also concluded more research is needed to help evaluate distracted driving laws and programs.
"Despite all that has been written about driver distraction, there is still a lot that we do not know," GHSA executive director Barbara Harsha said in a statement with the report.
"Clearly, more studies need to be done addressing both the scope of the problem and how to effectively address it."
The GHSA defined what distracted driving is, along with suggesting measures that can be taken by states and organizations to reduce it.
Countermeasures in recent years have concentrated on cell phone and texting distractions through laws and communications programs.
According to the report, laws banning hand-held cell use reduced use by roughly half when they were first implemented, but though the laws have had some long-term effect, hand-held cell phone use increased subsequently.
There is no conclusive evidence on whether hands-free cell phone use is less risky than hand-held use, the report said. Evidence is also lacking on whether cell phone or texting bans have reduced crashes or injuries.
Despite the need for more research and evaluation, the GHSA suggested a complete ban on cell phone use, hands-free or not, for novice drivers, who are the highest-risk. It also recommended a texting ban for all drivers.
As of June 2011, 30 states and the District of Columbia had prohibited the use of all cell phones by novice drivers and 41 states and Washington, D.C. had prohibited texting by novice drivers. Thirty-four states and the District of Columbia had enacted texting bans for all drivers, but the report found texting bans have proven difficult to enforce.
Because the research and data on these laws' effectiveness is not definitive, the report recommends the 41 states without handheld cell phone bans hold off and monitor existing laws before enacting their own.
The GHSA, the "States' Voice on Highway Safety," is a nonprofit association representing the highway safety offices of states, territories, the District of Columbia and Puerto Rico and works to improve traffic safety. The GHSA's members are appointed by their governors.
(Reporting by Molly O'Toole; Editing by Jerry Norton)