Courtesy Lou Corsaro.


Eastbound up to the US 22/I-78 split west of Allentown, with a cool diagrammatic sign. From I-81 to here, I-78 runs along the old four-lane freeway that once was just US 22 - the original 22 runs nearby as a two-lane road. Due to its age, some clearances are a little low and the design is highly substandard. I-78 was supposed to follow what is now US 22 up around Allentown/Bethlehem, across to Alpha, NJ, and back into the current alignment at Exit 3, meaning US 22 would be held captive until past Clinton. However, NJ was not able to upgrade US 22 to a freeway for those few miles, and PA's freeway isn't Interstate-quality near the NJ border anyway, so a whole new southerly alignment was built instead. I-78's Bethlehem child, I-378 (a babe born in Bethlehem...), then became PA 378, albeit a little belatedly. Maps showed I-78 along US 22 for quite awhile, though, and it was signed there despite the non-freeway discontinuity. See the US 22 page for more.


Not sure between which exits the last sign is, but Quakertown is on PA 309 and Bethlehem is Exit 67, so this is about right.


Between the last run of photos and these, I have the same complaint as on the westbound page - all these Allentown exits would be better served by an "Allentown - Next N Exits," versus the piecemeal way that leaves you guessing exactly when you've actually passed the city. Also, between the gore and the exit ramp sign for Exit 57 (the last two signs respectively), it appears that once this was an A-B exit, but configuration probably hasn't changed since this became I-78. Back when it was PA 309, the exit ramp was a lot tighter here, and the now WB-only Exit 58 immediately to the east was a full exit.


The last one is on the exit ramp, and is button copy. PA 145 becomes PA 309 at Exit 60, but since I-78 is currently multiplexed with PA 309 along 309's original path, it's a pretty tight diagonal corner, which is why the EB-NB and SB-WB movements happen to the west.


West Rock Rd. NB, turning left from the previous exit ramp photo and approaching PA 145.


Only the left "LAST EXIT" sign is button copy, and to prove it, click on that last photo. Not sure how that came about, unless it's due to a hapless trucker.


Running up the last exit ramp in Pennsylvania, but wait, there's more!


Phillipsburg is much closer than 5 miles from that sign, but a long loop around the south of Alpha means drivers have to go all the way to Exit 3 in Alpha, NJ, and then head back northwest. US 22, of course, runs right through it, and Phillipsburg is what prevented 22 from becoming I-78's through route.

Switch to the WB side
Roads intersecting I-78
Back to I-78 main page
Onto US 22 alone
Onto PA 309 alone

Follow I-78 into NJ
Follow Exit 51 to I-476
Follow Exit 51 to US 22
Exit 54 to US 222
Exit 75 to PA 611
Back to PA Roads
Back to Roads