New Jersey this week began seeking investors for $450 million in new state transportation bonds - borrowing that will put the state's highway building fund more than $4.6 billion in debt by year's end.

The new loan, which lawmakers authorized earlier this year, will cap four years of unprecedented borrowing that has seen the Transportation Trust Fund's debt rise by more than $3 billion since 1995. It is the second time since June the state has borrowed $450 million for transportation projects.

The upcoming transaction is separate from the $500 million in highway and bridge repair borrowing that voters approved Nov 2nd by a margin of 2 to 1.

The trust fund's heavy borrowing became an issue as state officials campaigned for voter approval of the $500 million bond issue. Critics said the state should consider boosting the 10.5 cents-per-gallon gas tax or dedicating other state tax revenues to transportation costs before borrowing more.

The trust fund will need every cent of gas tax revenue it is scheduled to receive for the next 15 years just to repay the outstanding debt. With the new $450 million bond issue presented to investors this week, the state's annual debt payments for transportation will surpass $400 million.

Overall, total state debt has reached $15 billion, an increase of almost $11 billion since 1990, state records show.