beyond the mid-county interchange, interstate 476 enters the pennsylvania turnpike system, interchanging with interstate 276 and continuing north as the northeast extension of the pennsylvania turnpike. the route continues through the philadelphia suburbs and has an interchange with pennsylvania route 63 near lansdale that serves the north penn valley region. past this interchange, the route enters a more rural setting of woods and farms, crossing into bucks county and coming to an interchange with pennsylvania route 663 near quakertown. the northeast extension continues north into lehigh county, part of the lehigh valley metropolitan area, past the pa 663 interchange. here, it has a ramp to the dual-access allentown service plaza in upper macungie township, and just north of it, i-476 interchanges with u.s. 22 (lehigh valley thruway) near allentown, which offers an indirect connection to pennsylvania route 309 and interstate 78.