In 1996, the I-476 designation was affixed to the pre-existing Northeast Extension of the Pennsylvania Turnpike, replacing Pennsylvania Route 9 (PA 9). This was an older four-lane pre-Interstate limited access highway. Of earlier design, its cross section was very narrow, with only between opposing lanes of traffic in places. This extended I-476 north of Plymouth Meeting to Clarks Summit (near Scranton) as a part of the Pennsylvania Turnpike system. I-476 connected to the Northeast Extension at a state-of-the-art three-level interchange. This provided direct access to both I-276 east and I-476 north, now on the Northeast Extension. With the re-designation of the Northeast Extension, I-476 surpassed I-495 in Massachusetts as the longest auxiliary Interstate Highway, a record it will hold until the completion of I-369 in Texas. I-476 was widened to six lanes from the Mid-County Expressway to Lansdale between 2011 and 2017.