The Texas Department of Public Safety is asking for witnesses to help in the investigation of a Tuesday morning collision that injured a Cedar Park couple while they were riding a two-person bicycle.

Angie Hughes, 31, was in critical condition Tuesday afternoon at University. Medical Center Brackenridge, according to DPS spokesman Lisa Block. Her, husband, Samuel Hughes, 47, was in fair condition at Brackenridge.

Susan Madson, 54, of Cedar Park, the driver of a 2005 Dodge Stratus that collided with the bicycle, was not hurt, Block said.

Investigators are trying to determine what might have caused the 5;50 a.m. crash on southbound Parmer Lane at Dallas Drive in North Austin, Block said.

No charges have been filed in connection with the collision, Block said.