Although the New Jersey Department of Transportation (NJDOT) had been construction-oriented in the past decades, NJDOT began shifting its focus to maintaining and preserving the existing transportation infrastructure while providing integration of the state's transportation network. As the 20th century came to a close, the 1990s saw the the completion of New Jersey's interstate highways and the creation of a strong, reliable transportation system.

There were six NJDOT Commissioners that led the Department through the 1990s: Tom Downs, Kathy Stanwick, Dennis Keck, Frank Wilson, John Haley and James Weinstein.

1991:

• The final section of Route 18 was opened, providing 40 continuous highway miles from New Brunswick to Wall Township.
• The Adopt-A-Highway Program began, a community involvement program which helps to keep New Jersey's highways clean and beautiful.

1993:

• The final 20.4 mile 'missing link' of I-287 was opened. The interstate begins at the Outerbridge Crossing and ends at the New Jersey/New York border, connecting to the New York State Thruway in Suffern, New York.
• As part of the Federal Clean Air Act, New Jersey was the first state in the nation to enact legislation for an Employer Trip Reduction (ETR) program.
• The Emergency Service Patrol, a roadside assistance program for motorists, began in Camden and Morris counties.

1994:

• The I-80 High Occupancy Vehicle (HOV) Diamond Express lane opened to help improve air quality and reduce congestion on New Jersey's roadways.

1995:

• The Trenton Complex, a three mile segment of I-295, the new Route 29/I-195/I-295 interchange and the new Routes 29 and 129 opened, completing the last missing piece of interstate highway in New Jersey.
• The initial 5.3 mile Diamond Express HOV lane opened on I-287.

1996:

• The second segment of the I-287 Diamond Express HOV lane opened, extending the HOV lane to 12 miles.
• Route 29 was designated as a Scenic Byway, New Jersey's first Scenic Byway.

1998:

• The final section of the I-287 Diamond Express HOV lane opened (one year ahead of schedule) making the 21-mile HOV lane one of the longest in the nation.

1999:

• Hurricane Floyd caused major damage on New Jersey's roadways such as sinkholes on Route 23, Route 9W and I-78. Flooding closed Route 1 and a bridge collapsed on Route 46, closing the eastbound lane for six days.
• The newly constructed NJ TRANSIT Hamilton Station was opened.
• The Hudon-Bergen Light Rail Transit System, a 20.5 mile system between Bayonne and Ridgefield Park opened its first segment between Jersey City and Hoboken.

*Acting Commissioner