The Texas Transportation Institute's study warning of the potential dangers of HOV lanes has forced transportation planners to take a hard look at the issue. The Texas researchers had found a 41-56 percent increase in accidents where carpool lanes were only separated from general purpose lanes by a paint stripe. In response to these findings, seven states including California and New York will examine the safety issue and produce a report with safety recommendations this year, according to the Wall Street Journal.

The Journal also reports that Maryland's top transportation engineer looked at accident data in light of the Texas study and found the HOV lanes on I-270 have an accident rate double the statewide average.

Last year, the Midwest Research Institute reported an 11 percent increase in Southern California HOV lane roads and roads where lanes narrowed.

Nolanda Holder was driving in the HOV lane on Interstate 635 in north Dallas this year when a car in front of her illegally veered across the double white lines to avoid a traffic tie-up in the regular lanes. She slammed on her brakes, but the minivan behind her couldn't stop in time and smashed into her pickup truck, according to a police report. Medics were called to treat a passenger in the front seat.... There is increasing evidence that adding an HOV lane can lead to more accidents such as the one that smashed up Ms. Holder's truck.