 The highway comes to an eastbound exit and westbound entrance with Rock Road that provides a connection to PA 145 in Summit Lawn, at which point it crosses into Upper Saucon Township.Following this, the freeway turns southeast and comes to an interchange with the southern terminus of PA 145, at which point PA 309 splits from I-78 by heading southeast on a surface road toward Quakertown.From here, I-78 turns northeast, narrowing to four lanes with the median changing from a Jersey barrier to a grassy median.