The deadline for the regulations was to have been Dec. 31, the fourth delay in standardizing rear visibility rules since Congress approved legislation in 2007, The Detroit News reported Tuesday.
The regulations are aimed at helping to eliminate blind zones behind vehicles which can hide the presence of pedestrians. It could lead to eventual "backup cameras" on all vehicles sold in the United States, the newspaper said.
"The department remains committed to improving rear view visibility for the nation's fleet and will issue a final rule upon competition of the regulatory review process," a statement from the agency said.
Notable deaths of 2014 [PHOTOS]