I-90 highlighted in red
|Maintained by PennDOT|
|Length||46.297 mi  (74.508 km)|
|West end||I-90 at Ohio state line|
US 6N near
I-79 near Erie
US 19 near Erie
I-86 near Erie
US 20 near State Line
|East end||I-90 / New York Thruway at New York state line|
Within the U.S. state of Pennsylvania, Interstate 90 spans 46.297 miles (74.508 km), all within Erie County, from the Ohio border near West Springfield to the New York border near North East. I-90 is the primary west–east highway in the Erie area, passing south of downtown and interchanging with Interstate 79, which connects downtown Erie to southern Pennsylvania and beyond, and Interstate 86, linking Erie to the Southern Tier of New York. U.S. Route 20, which interchanges with I-90 near the New York-Pennsylvania border, parallels I-90 across the county.
I-90 enters Pennsylvania from Ohio in Springfield Township, Erie County, heading east as a four-lane freeway through rural areas of fields and woods. The road has an eastbound rest area before it reaches an interchange with US 6N near West Springfield. The next exit is for PA 215 near East Springfield. The freeway enters Girard Township and curves to the northeast. I-90 passes through a corner of Platea before it crosses back into Girard Township and interchanges with PA 18. The roadway continues through more rural areas and crosses Elk Creek. The highway crosses into Fairview Township, where it has an exit for PA 98. I-90 curves more to the east and heads into McKean Township. Here, it has an interchange serving PA 832. The highway passes through more rural areas with some nearby development and reaches a cloverleaf interchange with I-79, which provides access to the city of Erie to the north.  
A short distance past I-79, the freeway enters Summit Township and heads northeast to an interchange with US 19 in a commercial area. I-90 runs through wooded areas with nearby suburban development and comes to the PA 97 near Presque Isle Downs and Casino. The highway passes through a corner of Greene Township prior to entering Millcreek Township, where it has an exit for PA 8. The roadway briefly crosses back into Greene Township before it heads into Harborcreek Township. Here, I-90 has an interchange with PA 290/ PA 430 that provides access to Penn State Erie, The Behrend College. The freeway heads back into rural areas of farms and woods, coming to the PA 531 exit. I-90 crosses into Greenfield Township, where it has a trumpet interchange with the western terminus of I-86. The roadway enters North East Township and continues through more rural land. The freeway reaches an interchange with PA 89, which provides access to the borough of North East to the north. Farther northeast, the highway passes through agricultural areas and comes to an interchange serving US 20 near State Line. I-90 has a westbound welcome center before it comes to the New York border, where it continues east into that state as part of the tolled New York State Thruway.  
What is now I-90 was originally planned as part of the Pennsylvania Turnpike system in the 1950s.  With the creation of the Interstate Highway System in 1956, this road would be dropped from the turnpike system and would be built as a part of I-90.   I-90 was completed through Pennsylvania by 1960.  In 2007, a major pileup forced a 15-hour closure of the entire stretch of I-90 in Pennsylvania due to winter storm whiteout conditions. 
The entire route is in Erie County.
|Location||mi ||km||Old exit|
|Springfield Township||0.000||0.000||I-90 west – Cleveland||Ohio state line|
|3.034||4.883||1||3||US 6N – West Springfield, Cherry Hill|
|6.173||9.934||2||6||PA 215 – East Springfield, Albion|
|Girard Township||9.613||15.471||3||9||PA 18 – Girard, Platea|
|Fairview Township||15.586||25.083||4||16||PA 98 – Fairview, Franklin Center|
|McKean Township||18.383||29.585||5||18||PA 832 – Presque Isle, Sterrettania|
|21.913||35.266||22||I-79 – Pittsburgh, Erie||Signed as exits 22A (south) and 22B (north); I-79 exit 178|
|Summit Township||24.365||39.212||6||24||US 19 ( Peach Street) – Waterford|
|26.918||43.320||7||27||PA 97 (State Street) – Waterford|
|Millcreek Township||29.322||47.189||8||29||PA 8 (Parade Street) – Hammett|
|Harborcreek Township||32.149||51.739||9||32||PA 290 / PA 430 ( Bayfront Connector) – Wesleyville, Colt Station||Eastern terminus of PA 290|
|34.622||55.719||10||35||PA 531 – Harborcreek, Phillipsville||Westbound exit sign omits Phillipsville|
|Greenfield Township||36.516||58.767||10A||37||I-86 east – Jamestown||Western terminus of I-86; I-86 exit 1|
|North East Township||40.563||65.280||11||41||PA 89 – North East|
|44.670||71.889||12||45||US 20 – State Line|
|46.297||74.508||I-90 east / New York Thruway east – Buffalo||New York state line|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
- Bureau of Maintenance and Operations (January 2015). Roadway Management System Straight Line Diagrams (Report) (2015 ed.). Pennsylvania Department of Transportation. Retrieved June 30, 2015.[ permanent dead link]
- Google (November 6, 2013). "overview of Interstate 90 in Pennsylvania" (Map). Google Maps. Google. Retrieved November 6, 2013.
- Erie County, Pennsylvania Highway Map (PDF) (Map). PennDOT. 2012. Retrieved November 6, 2013.[ permanent dead link]
- Dakelman, Mitchell E., Schorr, Neal A. (2004). The Pennsylvania Turnpike. Images of America. Mount Pleasant, SC: Arcadia Publishing. ISBN 0-7385-3532-X.CS1 maint: Multiple names: authors list ( link)
- Official Numbering for the National System of Interstate and Defense Highways (Map). American Association of State Highway and Transportation Officials. 1957. Retrieved November 6, 2013.
- Official Map of Pennsylvania (front) (PDF) (Map). Pennsylvania Department of Highways. 1960. Retrieved November 6, 2013.[ permanent dead link]
- "I-90 Reopens After Fatal Crash Near Erie, Pennsylvania". Fox News. January 26, 2007. Retrieved June 2, 2012.
- "Pennsylvania Exit Numbering" (PDF). Pennsylvania Department of Transportation. Retrieved October 2, 2007.