Pennsylvania exit letters

[Poiponen13]

I found some uses of exit letters in Pennsylvania on US 422 when browsing OpenStreetMap. They are in Kittanning and Indiana. What is their purpose?

[Hunty2022]

A = Southbound
B = Northbound

It's like any other multi-exit A-B system, just without the numbers.

That's my guess.

[Mr_Northside]

They're basically used on segments of freeway that don't use exit numbers (so most, but not all, non interstate freeways), but where there is a single "interchange", but with multiple exit ramps for it (like a cloverleaf, or however you'd term the interchange complex with 422 & 66 between Kittanning & Ford City)

[Alps]

These are also exiting State College to the north.

[rickmastfan67]

They're basically used on segments of freeway that don't use exit numbers (so most, but not all, non interstate freeways), but where there is a single "interchange", but with multiple exit ramps for it (like a cloverleaf,

They are also present on US-40 @ PA-Turnpike 43.

or however you'd term the interchange complex with 422 & 66 between Kittanning & Ford City)

It's called a cluster fuck. LOL!  Just add the missing ramp to trumpet part on the road into Kittanning, and remove that super long bridge ramp from EB US-422/NB PA-28 -> SB PA-66, and you'll have way less maintenance costs there.