The Information Superhighway (infobahn) is a term that was/is used to describe the Internet and digital communication. Generally speaking, it's a term that was/is used to refer to the Internet. Usage of the term was at it's peak in the 1990's: the term was popularised by Al Gore - a keen supporter of the Internet - and in the 1990's the Vice President of the United States of America. While the general assumption is that Al Gore coined the term - due to him using the term throughout his political career - research has suggested that the term was used from the 1940's to describe tele-communication systems. What is without doubt: is that Al Gore popularised the term and usage of the term in the 1990's.
Throughout the 1970's and 1980's Al Gore had a keen interest in computer science: he supported legislation that would increase public access to ARPANET in the 1980's, and managed to develop 'The High Performance Computing Act of 1991' (known of the Gore Bill). This Act of congress helped to fund many technological advancements / achievements; it is claimed it helped fund the development of Mosaic (the first graphical Web browser). The National Information Infrastructure (NII) was another result: which aimed to interconnect technology and was also referred to - by Gore - as the "Information Superhighway".
While Al Gore was often quoted as envisaging a computer/telecommunications system that could be used by the citizens of the United States, it was only until the World Wide Web was created in 1990/1 - the World Wide Web is a document system found on the Internet - that it became apparent to Al Gore that the Internet could become his envisaged "Information Superhighway". It was fortunate for computer scientists that the World Wide Web came to prominence at the same time that a key advocate/supporter of information technology came to power: Al Gore was the 45th Vice President of the United States (19932001).
Al Gore fell from national prominence (in the US) - due to his failed presidential campaign of 2000 - and use of the term "Information Superhighway" subsided and has largely become redundant (2014).