Did the abandoned PA Turnpike tunnels carry an interstate route number?

[crispy93]

Hi all, does anyone know if the abandoned PA turnpike carried an interstate highway route number when it (and the Rays Hill and Sideling Hill Tunnels) were still in operation? From what I've looked up, it seems like the PA Tpk was I-70S in the 50s and 60s, and the bypassed section closed in 1968.

Just wanted to know if those narrow, 1880s tunnels were ever part of the interstate highway system. Thanks!

[Beltway]

Hi all, does anyone know if the abandoned PA turnpike carried an interstate highway route number when it (and the Rays Hill and Sideling Hill Tunnels) were still in operation? From what I've looked up, it seems like the PA Tpk was I-70S in the 50s and 60s, and the bypassed section closed in 1968.
Just wanted to know if those narrow, 1880s tunnels were ever part of the interstate highway system. Thanks!

The Turnpike was added to the Interstate highway system in 1957.

In August 1957, the Bureau of Public Roads added the roadway to the Interstate Highway System upon the recommendations of various state highway departments to include toll roads in the system.

In April 1963, the state of Pennsylvania proposed renumbering I-80S to I-76 and I-280 to I-276 because the spurs of I-80S did not connect to I-80 in northern Pennsylvania.  The renumbering was approved by the Federal Highway Administration on February 26, 1964.  With this renumbering, the turnpike would carry I-80S between the Ohio border and Pittsburgh, I-76 between Pittsburgh and King of Prussia, I-70 between New Stanton and Breezewood, and I-276 between King of Prussia and Bristol.

https://en.wikipedia.org/wiki/Pennsylvania_Turnpike#Route_numbers

[briantroutman]

I've never seen the Turnpike marked as I-70S on any proposed route numbering maps. (The I-70S designation was, however, used from 1957-1964 on the toll-free expressway between New Stanton and Washington, PA while I-70 was routed via Pittsburgh.)

To the best of my knowledge, the earliest Interstate numbering proposal had the Pennsylvania Turnpike designated as I-80 from the Ohio line to the Harrisburg area–where it was to split into I-80N and I-80S. I-80N would pass through Allentown heading toward New York City (today's I-78), and I-80S would follow the Turnpike and Schuylkill Expressway to Philadelphia. But that plan didn't account for the Keystone Shortway route (today's I-80), which was just gaining traction as a late addition to the Interstate System in 1956-57. Early Interstate System maps propose a more northerly route along the US 6 corridor as an extended I-84–a plan that was dropped in favor of the Shortway.

In 1958, AASHTO decided that the Keystone Shortway would take the I-80 designation, and the Pennsylvania Turnpike and Schuylkill Expressway were penciled into the maps as I-80S. That said, Pennsylvania Department of Highways' 1960 state map shows no numbers on any segments of the Turnpike whatsoever–despite AASHTO's official designation. From all of the photographic evidence I've seen, I tend to believe that the PDH map somewhat more reflective of reality–that the Pennsylvania Turnpike Commission almost certainly never put up any I-80 shields, and it likely posted little to no signage of I-80S between 1958 and 1964. Perhaps a few shields haphazardly appended to existing signage at major decision points like Monroeville, but I expect little more than that.

I've never come across any I-80S signage in my years of looking at old Turnpike photography, but it anyone has anything to share, I'd be very interested in seeing it. About the only I-80S signage I've ever seen (period) is this newspaper clipping below from Ohio.

And one other note on the tunnels: I'd say it's a bit misleading to refer to the original 1940 Turnpike tunnels as "1880s tunnels" . None of the South Penn Railroad tunnels was completely bored through. Sideling Hill, for example, was bored for about half its length and only about half the width required for the Turnpike. The South Penn's Allegheny Mountain Tunnel was abandoned altogether for an entirely new tunnel built by the PTC in 1939-1940.

[PAHighways]

Yes and No.  While proposed designations such as I-80S were planned for the Turnpike, the only one that was actually posted was I-76 [and for a time 80S between Ohio and Exit 57/formerly 6].  The 1964 official state map, which was the first using the graphics set that was used from then through the 70s, did not have Interstate shields on the Turnpike but the following years did.

While Laurel Hill missed out on carrying 76 as it closed prior to that designation, Rays Hill and Sideling Hill both carried 76 as evidenced by the clip of the 1968 official state map posted in this section of earlier said page.

[crispy93]

While Laurel Hill missed out on carrying 76 as it closed prior to that designation, Rays Hill and Sideling Hill both carried 76 as evidenced by the clip of the 1968 official state map posted in this section of earlier said page.

Thanks, all. I did see that 1968 map but was initially unsure if the old or new alignment was in use at the time, since the map shows both.

[PAHighways]

The new/current alignment was marked with the under construction dashed line, and the now abandoned was solid.

SM-G965U

[Alps]

A slight addition to what you've written - From one old map I saw, I-76 and I-80S coexisted for some time before 76 was extended to fill in 80S. I believe that I-80 followed I-480 through Cleveland in the map I saw, while I-80S took the Turnpike from there. The eastward extension of 480 along the 422 corridor was considered as I-80 to tie in around Youngstown, and then I-76 was the road to Akron.

[roadman65]

A 1962 Esso Map of NJ did not even show I-276 (or I-280 then) on the PA Turnpike leading into NJ at that time.  I assume that a PA edition of the same year would not show any number on the whole system, but 1962 does predate the opening of the Ray and Sideling Hill Bypass as well as Laurel Hill and the other remaining tunnels twinning.

Even I-70 at Breezwood was built prior to the Rays Hill and Sideling Hill bypass which means if PTC and PennDOT (or their previous department) at the time built the connection right, there would be no problem today as the town there would have no economy boost to protect now.