Plans Unveiled to Improve I-83/PA 581 Interchange

[PAHighways]

A long overdue improvement to an antiquated interchange will soon become reality. Part of a master plan to improve I-83 from the New Cumberland exit to its terminus at Interstate 81, the project would see the current trumpet reconfigured as well as improvements to near-by interchanges.

http://www.yorkdispatch.com/news/ci_17839031

[mightyace]

The improvements should definitely help.

However, I was hoping that they would do away with the trumpet entirely rather than simply adding lanes to the through route. (I-83)

[vdeane]

What's wrong with the trumpet?  As long as there are enough lanes from the through routes (which, contrary to route numbering, is both I-83 and PA 581-83), I don't see the issue.

[Truvelo]

The problem with trumpets is not the number of lanes but the radii of the loops, in particular northbound I-83 to westbound 581 looks tight. This has the potential to cause delays to following traffic when big rigs have to slow to a crawl to negotiate the curvature without risk of flipping over. One of the worse examples in PA that I've experienced of this is I-79 exit 34 where the main turning movement is I-79 to I-70 west. This is a tight single lane loop with numerous signs warning of the curve.

[PAHighways]

Traffic slows to a crawl no matter if you are taking 581 or staying with 83 since either lane has to merge.  Another issue that slows traffic is the merge from Brandt Avenue.

Upgrading of the I-70/I-79 interchange is expected to begin this year.

[froggie]

Something else that's wrong with trumpets:  left-side exits and/or entrances, which pose operational problems.

This plan looks like a dumbed-down version of the master plan study.  The master plan recommended a semi-directional interchange here.

[vdeane]

Maybe it's because I'm from NY, but tight ramps at freeway-freeway interchanges don't strike me as anything unusual due to the Thruway.  Also, because I'm from the northeast, I recognize that highway numbers often don't match the through roads.  In this instance I would say the through road is the Harrisburg beltway, not I-83.

Looking in street view, traffic seems to use this a lot more as a split than an exit anyways.

[exit322]

Now all they need to do is improve all of I-70 east of I-79. 

[qguy]

This plan looks like a dumbed-down version of the master plan study.  The master plan recommended a semi-directional interchange here.

According to the master plan's website, this interchange improvement is part of a series of improvements (such as eliminating or reconfiguring nearby on- and offramps) which are considered "early action items," able to be accomplished much earlier than the recommendations in the master plan which will come much later.

[treichard]

One part of the multi-interchange improvement has already occurred: the ramp from Lowther Street WB to I-83 NB was closed without replacement as a safety improvement.  The new design is wise in not re-adding it.

The removal of the other Lowther St. ramps in the SE quadrant will be great.  It's a bad cross-merge situation right now for PA 581 EB traffic wanting to exit to Lowther just past this I-83 interchange as they have to cross the on-merging I-83 NB traffic.  The ramp density in this area is just too large and the ramps have short or no merge areas, though possibly it worked decades ago when speed limits were much slower.

A few years ago I wrote to PennDOT to ask if the US 15 & PA 581 interchange improvement would be sufficient for redesignating PA 581 as an Interstate.  I had assumed the number 581 was chosen a decade earlier with a I-581 in mind. They replied that the I-83 & PA 581 interchange would need some work, but at the time they didn't have plans to make PA 581 an Interstate.  Maybe keeping a substandard I-83 interchange prevents Interstate eligibility and they expected this result.

This plan looks like a dumbed-down version of the master plan study.  The master plan recommended a semi-directional interchange here.

I thought the same thing.  The design shown in the article doesn't change the low-speed I-83 SB to SB ramp to a higher-speed ramp.  While at least there are 2 lanes for that ramp, it's posted at 30 mph IIRC.  That retains rather than relieves the bottleneck since it cuts the possible traffic flow rate roughly  in half compared to a 55 mph ramp.

[vdeane]

How is it substandard with respect to PA 581?  It has the through traffic lanes!  It's clearly considered good enough for I-83, because I-83 is on it (though don't get me started on the PA 581/US 15 "improvement"; a freeway to freeway interchange should not involve stopping, and why one tight ramp/weave is bad but the others are OK is beyond me).  NY is even building a new interchange that is even more "sub-standard" than this: I-81/I-781.

[mightyace]

How is it substandard with respect to PA 581?  It has the through traffic lanes!  It's clearly considered good enough for I-83, because I-83 is on it

It is probably "grandfathered" in as was the rest of the old US 111 freeway.   In addition, back in the mid-80s, they still had "slip ramps" to local businesses parallel to the highway that made them defacto service plazas.  Not all of these ramps had exit signage.  These have long since been removed.

Also, the highway had many low speed sharp 90 degree right and turn exits.

a freeway to freeway interchange should not involve stopping

Tell that to the to the various toll authorities in NY, PA, NJ, OH, IN, etc!

and why one tight ramp/weave is bad but the others are OK is beyond me

The through ramps for I-83 are not freeway speed (55mph plus).

[vdeane]

Standards are pointless if you're going to enforce them for certain roads.  They should either ditch the standards or force the older interstates to upgrade.  Also, IMO it is completely rediculous to force an older interstate to upgrade simply because it's going to meet a newer one if it would otherwise not have to upgrade, especially in this case since PA 581 ends at I-83.

I don't know of a single freeway-freeway interchange that involves stopping in NY, at least for people with EZ-PASS, exempting of course missing connections that have to be made on surface streets.

[Alps]

I don't know of a single freeway-freeway interchange that involves stopping in NY, at least for people with EZ-PASS, exempting of course missing connections that have to be made on surface streets.

Well that's the definition. 278/495, half the movements involve stopping, as an example. 478/FDR, there's a traffic light at the end of the tunnel. This just counts "complete" interchanges, leaving out such gems as FDR/95 (two whole movements out of eight).

[vdeane]

Personally I wouldn't consider 478/FDR and interchange so much as an intersection.  Looking at Google Maps, it doesn't look like 278/495 should involve stopping for the completed movements (7/8), but I'm less familiar with downstate so I can't really comment.  Maybe I should have added a qualifier for traffic.

[Alps]

Personally I wouldn't consider 478/FDR and interchange so much as an intersection.  Looking at Google Maps, it doesn't look like 278/495 should involve stopping for the completed movements (7/8), but I'm less familiar with downstate so I can't really comment.  Maybe I should have added a qualifier for traffic.

OK, let's pretend I said 678 instead of 278.

[Buummu]

The interchange should be redesigned as directional T instead of a trumpet...