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The Pennsylvania State Route Numbering System
Other Numbering Ideas

The numbering system of 1928 had clear rules for numbering all the state routes, as mentioned on the parent routes, child routes, and spur routes pages. By the mid-1930s, new state routes needed to be numbered, and many were numbered according to the 1928 rules. For example, 746 was added to the x46 family, 664 and 764 were added to the x64 family. Other new routes were given numbers chosen according to other numbering ideas. Some of these ideas were similar to the 1928 numbering rules, such as numbering new routes off of the last two digits of spur routes (e.g., numbering 796 near 896), while other ideas led to isolated sequential numbering (e.g., numbering 377 near 376) or creating new, small quasi-families of route pairs (e.g., 259 and 359). In later decades, and especially upon the state route renumbering effected by the designation of interstate highway numbers, seemingly random numbers were assigned to some routes, while new non-interstate expressways received recycled or interstate-like numbers.


Child Routes of Spur Routes

By the early 1930s, and in a recent case in the 1990s, a few new routes near spur routes were assigned numbers whose last two digits matched those of the spur route. These new routes used high child route numbers (typically the first digit was 6 or 7) and high parent route numbers as a base because many parent routes 60-99 had small families, and so the 6xx and 7xx numbers had not been used. There are six examples of this rule:

New RouteExisting Spur RouteRemarks
660 exists today near Wellsboro in Tioga County. 960 was a spur off US 6/7 and may have intersected 660.
780 is now 880 from 477 to 192 in Clinton and Centre Counties. This 780 is the original one; the 780 northeast of Pittsburgh appeared shortly thereafter.
582 led from US 119 into Blairsville as an alternative to US 119 and US 22/US 119 in Indiana County. 982 was a spur off US 22/3 just to the west.
696 initially connected US 11 near Chambersburg to 997 near 996 in Scotland in Franklin County. 996 was a spur off US 30/1, to which 996 came very close.
796 first appeared where 896 is today south of US 1/12 in Chester County. 896 was a spur off US 122/42 (now 10), to which 796 came close.
424 is probably a coincidence, but the number was designated in the late 1990s for a new southern bypass of Hazleton, where 924 begins. 924 was a spur off 29 (now 309), which 424 intersects in Luzerne County.


Sequential Numbering

While new routes of the 1930s that appeared near spur routes were numbered like new child routes, new routes near parent or child routes were numbered sequentially similar to spur routes, i.e., the new route number was one more than the existing route number (e.g., numbering 377 near 376). Here are the four instances.

New RouteExisting Parent or Child RouteRemarks
91 90 91 was recycled after US 13 took over the original 91. The later 91 paralleled 90 (now 191) from US 6/US 106/7 (now US 6) to 371 in Wayne County. The choice of 191 to replace 90 when I-90 was designated may have had something to do with this 91.
248 247 248 was a southward extension of 247 from US 6 to 348. 248 also fits into the newer quasi-x48 family (see next section). 248 is now part of 247, and 248 has been reassigned.
377 376 377 connected 376 (now 747) to US 522. 377 is now part of 994.
428 427 Exists between 408 and 8 in Crawford and Venango Counties, paralleling 427 a few miles to the east.


New Quasi-Families

Other new routes appeared in the 1930s in pairs whose last two digits matched and hundreds digits differed by one, making quasi-families of just two members. These routes differ from the Child Routes of Spur Routes in that both routes in the pair are new, and their numbers fall in the child route number range 101-799. Some state route additions to the US x19 and US x22 families are also included here, mainly because they do not fit elsewhere.

New RoutesRemarks
196 296 196 and 296 exist in Wayne and Monroe Counties and intersect twice, each ending at the other near Lake Ariel.
248 348 248 (now 247 south of US 6) and 348 intersected in Mount Cobb in Lackawanna County. 248 may also have been numbered sequentially from 247 (see previous section).
259 359 259 exists between US 422 and US 30 in Indiana and Westmoreland Counties, once extending north to US 119. Some 35 miles to the west, 359 connected Kittanning with 56.
371 471 Part of 371 exists from 171 to the New York state line in Susquehanna and Wayne Counties. To the northwest in Susquehanna County, 471 connected 858 with Montrose.
319 519 319 (now 857) appeared as a route paralleling US 119 in Fayette County, while 519 was numbered as a former alignment of US 19 in Allegheny and Washington Counties. Coincidentally, 819 appeared paralleling US 119 further north much like 319 did further south.
722 Appeared as a connecting route to US 222 (now 272).


Extended Families

At least one example exists where all the numbers for a family were assigned or forbidden (xx, 1xx, 2xx, ..., 7xx) and so the 8xx child route was assigned. The x13 family used up numbers 113-713, and 13 was forbidden to avoid duplication with US 13, and so the seventh child route was assigned as 813. The number 813 was free for assignment because the spur routes were numbered only consecutively from about 819 to 999. There are other coincidences that appear to follow in the same category as 813, but are merely spur routes 832-999 that happen to share the last two digits with an intersecting parent route: 841 (spur off 22, intersected 41) and 864 (spur off 64). Additionally, 891 appeared as a child route of 91 (now US 13) even though 691 and 791 had not been assigned.


New State Route Expressways

Beginning in the 1950s, expressway construction blossomed across the state as traffic volumes and congestion increased in several areas and as the Interstate highway system was effected and built. Not all expressways became part of the Interstate highway system, and those that did not instead received US highway or state route designations. While many existing designations were moved from a bypassed highway to the new expressway bypass, other expressways were built where a new number would be needed. These expressways were typically given one of two types of state route numbers: a low one- or two-digit number, or a three-digit number whose last two digits matched an intersecting Interstate highway.

For the recent one- and two-digit expressways, odd numbers were assigned to north-south expressways and even numbers to the east-west expressways. Two-digit numbers were often chosen instead of available one-digit numbers. The currently unused one-digit numbers (2, 4, 7, and 9) could be reserved for other uses.

One- and Two-Digit Expressways

New ExpresswayRemarks
9 Was assigned to the north-south Northeast Extension Pennsylvania Turnpike, now I-476 north of I-276. Of the unused odd numbers, 7 and 9 were the lowest available, but 9 was chosen instead of 7.
12 Assigned to the east-west Warren Street Bypass in northern Reading in Berks County when US 222 was relocated to the Northern Bypass in the 1990s. Of the unused even numbers, 12 was the lowest two-digit number, though 2 and 4 were also available.
33 Assigned to the north-south expressway connecting I-78 to I-80 in Northampton and Monroe Counties. Of the unused odd numbers, 33 was the lowest two-digit number, though 7 was also available.
43 Assigned to the Schuylkill Expressway, now I-76 from I-276 to the New Jersey state line. 43 was the lowest two-digit number, though 7 and 9 were also available.
43 Assigned to the incomplete Mon-Fayette Expressway from Pittsburgh to Morgantown, WV in Allegheny, Washington, and Fayette Counties. 43 was the lowest two-digit number not currently in use in Pennsylvania and West Virginia.

Other expressways had an existing two-digit number extended or bypassed (8, 28, 29, 56, 60, Business 60, 63).


Three-Digit Expressways

New ExpresswayRelated InterstateRemarks
283 283283 connects directly to I-283 and serves the Harrisburg-Lancaster corridor.
581 81 581 completes the Capitol Beltway with I-81 and I-83 and intersects both interstates. 581 was the lowest unused x81 number when 581 was assigned.


Avoiding Duplication with Interstate Numbers

When Interstate highways were numbered, it was desired to renumber state routes that had the same numbers as the Interstates. These renumberings are covered on their own page.


Decommissioned US Routes and Interstates

Several US and Interstate highways lost their special status and were redesignated as state routes. In most cases, the same number was used for the US or Interstate route as for the replacement state route. Most of the US routes that were decommissioned were entirely in Pennsylvania or were short (< 300 miles), and were decommissioned when US route highway criteria were reevaluated in the 1960s. Other US highways were decommissioned when bypassed by an Interstate or truncated to an Interstate. Below are the similarly numbered state routes that appeared as a result of decommissioning US and Interstate highways.

New DesignationOld DesignationRemarks

106US 106 became three pieces as it originally was: 706 (67 in 1928) west of US 11, 106 (47 in 1928) east of US 11 to US 6, and 652 (19 before 1928) east of US 6 to the New York state line. 652 matches NY 52 at the state line.
120 120120 kept its number.
222 222 US 222's north end was truncated to I-78/PA 309. The portion of US 222 that continued to Allentown kept the number but was redesignated a state route. (Coincidentally, the southern end of US 222 in Maryland has a similar story, having been truncated to US 1 when it once extended to US 40. The southern segment is now MD 222.)
230 230230 kept its number, though the southern portion is now 283.
309 309309 kept its number for most of its length.
378 378I-378 was built as a spur off I-78/US 22 (now US 22) north of Bethlehem in Lehigh County. Later, I-78 was moved to the freeway to the south, and so I-378 could not keep an interstate designation because it did not connect to any interstates. 378 was also extended south to 309.
611 611611 kept its number for most of its length.


Similar Numbers

Some lengthy two-digit state routes were partitioned into shorter routes, especially when long stretches of the route carried more than one number. A few of these partitioned routes gained three-digit numbers in which two of the digits matched the original number's digits. For example, part of 14 became 147, part of 53 became 523, and part of 115 became 118. Whether these numbers were methodically selected or randomly assigned is not known.


Duplicate Numbers

There have been several occasions where two disconnected routes were simultaneously given the same number, and often even the same designation as a state, US, or Interstate highway. Several examples survive today (17, 29, 43, 86, 99, 222, 283, 380, 422) for various reasons, as did earlier examples (e.g., 780). In modern times, a few of these duplications are resolved by assigning the more minor route a different SR number than the signed PA number (e.g., I-283 is SR 0283 and PA 283 is SR 0300).

Duplicated RoutesRemarks
17 17 17 The original 17 was the Benjamin Franklin Highway, now mainly US 422, US 22, US 322, and US 422 from west to east. The Southern Tier Expressway (NY 17/Future I-86) in New York travels through a few miles of Pennsylvania in Bradford County. The expressway also enters Pennsylvania in Erie County, originally as 17, then I-86/17, and now as I-86 alone.
29 29 29 was originally one contiguous route until broken in two when US 309 was relocated to the center section. 29 remains in its two pieces, both signed as PA 29 and designated as SR 0029.
43 43 43 is the incomplete Mon-Fayette Expressway, currently in two pieces until the center section is built.
46 46 In 1928, the parent route 46 was designated and remains today. Soon thereafter, a second, much shorter, short-lived 46 was assigned to current 970 between 53 and 350.
46 46 Later on, New Jersey's US 46 replaced 987 to end at US 611 for a few years. All three 46s existed for a brief time.
60 60 60 was like 43, existing in two pieces, until the center section was built as PA Turnpike 60.
72 72 72 was quite similar to 46. The 1928 parent route 72 still exists north of Lancaster and was replaced by US 222 south of Lancaster. Also in 1928, a short, shorter-lived 72 was assigned in Pittston from US 309 (now Business 309) to US 11.
86 86 I-86 was designated recently. The duplication with 86 is resolved in the SR numbers: I-86 is SR 0086 and 86 is SR 0886.
99 99 I-99 and 99 share both posted numbers and SR numbers 0099.
111111 US 111 may have existed in two pieces, separated from Northumberland to Harrisburg by US 11. The northern piece is now US 15, I-180, 405, and 147, and the southern piece is bypassed by I-83.
120120 US 120 may have been two pieces like US 111, separated from Lock Haven to Northumberland by US 220 and US 111. The western piece is now 120, and the eastern piece is now 61 and US 422.
222 222 US 222's north end was truncated to I-78/PA 309. The portion of US 222 that continued to Allentown kept the number but was redesignated a state route. US 222 also remains.
283 283 The 283 expressway connects Lancaster to I-283. The duplication is resolved in SR numbers: I-283 is SR 0283 and PA 283 is SR 0300.
295 295 I-295 is planned to enter PA on current I-95 north of I-276. This renumbering may create a duplication with 295 in York County.
380 380 380 was not renumbered when I-380 was built because the Interstate was originally designated I-81E and I-81S. The duplication is resolved in SR numbers: I-380 is SR 0380 and PA 380 is SR 400.
422422The Benjamin Franklin Highway (originally 17 in 1928) ran across the state in 1928, but concurrently with the William Penn Highway (originally 3) and Susquehanna Trail (originally 4) in the middle of the state. The western part of 17 was designated US 422, and the eastern part was initially US 120 and then US 422 so that the Benjamin Franklin Highway could have come closer to having one continuous number. To have connected the US 422/17s would have meant a very long multiplex with US 22/3 (and US 11/4/US 22/3/US 322/5) or else severing US 22 in two, so the two pieces of US 422 remain disconnected, unlike the original 17.
780 780 Both 780s appeared in the 1930s. The eastern 780 was associated with 880, while the western 780 was a child of the x80 family. The western 780 still remains, while the eastern 780 is now 880 from 477 to 192.
891 891 The northern 891 was an original spur off US 120/45, while the southern 891 was assigned from Chester to the Delaware state line.

In two cases of current Interstate/state route duplications (283 and 380), the SR number of the state route was changed to the least multiple of 100 greater than the posted number (300 and 400). In the 1930s, when US 62 was first designated in Pennsylvania, PA 62 was renumbered to PA 100 according to a similar convention, though this renumbering occurred several decades before the SR system was devised. There are two more Interstate-state route duplications today: 86 (PA 86 is now SR 886) and 99 (both I-99 and PA 99 are SR 99).


Matching Numbers at State Borders

There are several examples of Pennsylvania and a neighboring state agreeing to number or renumber a border-crossing state route with the same or similar number on both sides of the state line. In many cases, the exact same number can be chosen by both states (e.g., PA 43 & WV 43, PA 669 & MD 669, PA 52 & DE 52, PA 73 & NJ 73, PA 426 & NY 426). In other cases, one state cannot perfectly match the number across the state line because its number is already in use, and so it picks a number whose last two digits match (e.g., PA 285 & OH 85, PA 652 & NY 52). These renumberings are covered on their own page.


Random Numbers

Before the Interstate highway system was begun in the late 1950s, almost every route number could be classified into (1) the 1928 numbering system, (2) the US highway system, or (3) one of the categories listed above on this web page. A few apparently random numbers had appeared by this time. Some appeared with the 1928 system (e.g., 185, 278, 328, and 528), and others appeared later (e.g., 378, 405, and 456). With the renumberings taking place with the creation of the Interstate system, random numbers were assigned to several state routes, especially to three-digit state routes whose numbers duplicated Interstate numbers (e.g., 176 was renumbered to 475, 276 to 747, 376 to 829), and also to new routes designated later on (e.g., 181, 182, 534, and 737).

A list of the randomly numbered routes is given here, and remarks about these routes (and the non-randomly assigned routes) are given on the Route Families and Spur pages linked below.

Spur Routes:800–849850–899900–949950–999


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