The design and construction oversight of the Driscoll Bridge was the result of a collaboration between three groups of engineers: the New Jersey Highway Authority staff, the consultants to the Authority for the overall Garden State Parkway project, and the bridge design firm of D.B. Steinman of New York City.
Harold W. Griffin, chief engineer of the New Jersey Highway Authority, carried overall responsibility for the Driscoll Bridge project and was assisted by Harry A. Hartman, supervisor of construction. The firm of Parsons, Brinkerhoff, Hall & McDonald served as general consultants for the Parkway project, and Morris Goodkind served as consulting bridge engineer for the Parkway's bridges. Goodkind was chief bridge engineer at the New Jersey State Highway Department at the time and had been responsible for the design of the Edison Bridge fourteen years earlier.
I figured it wasn't "by the book measurement" widest, but 15 lanes is impressive nonetheless.
This bridge might be the widest bridge that only carries vehicular lanes, but "Big Bridge" in Lockport, New York is the widest bridge I know of at 400 feet wide, which is over three times the width of Discoll Bridge: http://www.bridgehunter.com/ny/niagara/main-street/
As long as we are talking about wide bridges, its interesting to note that the George Washington Bridge carries only one less lane than this bridge, but GWB is a double-deck bridge so its not nearly as wide. Both this Driscoll Bridge and GWB clearly have some of the largest ADTs for bridges in the country. http://www.bridgehunter.com/ny/new-york/george-washington/