{{Short description|State highway in northeastern Ohio, US}} {{Use American English|date=May 2025}} {{Use mdy dates|date=January 2025}} {{Infobox road |state=OH |type=SR |route=170 |map=OH 170 map.svg |length_mi=36.64 |length_round=2 |length_ref=<ref name="sld">{{cite web |url=http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Pages/Straight-Line-Diagrams.aspx |title=Technical Services Straight Line Diagrams |author=Ohio Department of Transportation |author-link=Ohio Department of Transportation |access-date=April 30, 2010}}</ref> |established=1924 |direction_a=South |terminus_a={{jct|state=OH|US|30|SR|7|SR|11}} near Calcutta |junction= *{{jct|state=OH|US|224}} in Poland *{{jct|state=OH|I|680}} in Youngstown *{{jct|state=OH|SR|7}} in Youngstown |direction_b=North |terminus_b={{jct|state=OH|US|62}} in Youngstown |counties=Columbiana, Mahoning |previous_type=SR |previous_route=169 |next_type=SR |next_route=171 }} thumb|right|200px|Intersection with State Route 154 in Negley '''State Route 170''' ('''SR 170''') is a north–south running state route located in Mahoning and Columbiana counties in northeast Ohio. It runs within a few miles of the Pennsylvania border for much of its route as it passes through the eastern parts of the two counties. The southern terminus is at an interchange with U.S. 30, State Route 7, and State Route 11 near Calcutta, and the northern at U.S. 62 in Youngstown. ODOT extended the northern terminus from the previous point of Interstate 680, changing signs on July 16 and 17, 2008.<ref name=vindy>{{cite news |title=Sign work, I-680 restrictions to be done today |url=http://www.vindy.com/news/2008/jul/17/sign-work-i-680-restrictions-to-be-done-today/ |work=The Vindicator |date=2008-07-17 |access-date=2009-05-12 |archive-date=September 27, 2011 |archive-url=https://web.archive.org/web/20110927131332/http://www.vindy.com/news/2008/jul/17/sign-work-i-680-restrictions-to-be-done-today/ |url-status=dead }}</ref>
==History== In 1924, it became the original state highway where it routed from East Palestine to Petersburg. In 1931 the highway extended to East Liverpool along a previously unnumbered road. Later in 1962 it was extended to {{convert|1|mi|km|adj=on}} north of North Kingsville along previous route 90. The road was truncated at {{convert|3|mi|km}} north of Poland in 1970.<ref name="system">[http://pages.prodigy.net/john.simpson/highways/170.html Route 170] by John Simpson{{unreliable source?|failed=y|date=December 2013}} {{webarchive|url=https://web.archive.org/web/20080307232648/http://pages.prodigy.net/john.simpson/highways/170.html|date=March 7, 2008}}</ref> In 2008, it extended {{convert|3|mi|km}} to U.S. 62 in Youngstown along the former Route 625.<ref name="vindy" /><ref name="SLD2008Changes">{{cite web|url=http://www2.dot.state.oh.us/techservsite/availpro/Road_%20Infor/SLD/updates_2008/MAH.htm|title=ODOT SLD: Mahoning County 2008 Updates|date=January 1, 2008|publisher=Ohio Department of Transportation|access-date=2009-02-18}}{{Dead link|date=April 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
==Major junctions== {{OHinttop}} {{OHint |county=Columbiana |cspan=7 |location=Calcutta |mile=0.00 |type= |road={{jct|state=OH|US|30|SR|7|SR|11|road|Substation Road}} |notes=Interchange }} {{OHint |location=Negley |lspan=2 |mile=11.18 |type=concur |road={{jct|state=OH|SR|154|dir1=east|location1=Beaver Falls, PA}} |notes=Southern end of SR 154 concurrency }} {{OHint |mile=11.24 |type=concur |road={{jct|state=OH|SR|154|dir1=west|city1=Lisbon}} |notes=Northern end of SR 154 concurrency }} {{OHint |location=East Palestine |lspan=2 |mile=14.57 |type= |road={{jct|state=OH|SR|46|SR|558|dir1=north|dir2=west|name2=Main Street}} |notes=Southern terminus of SR 46; eastern terminus of SR 558 }} {{OHint |mile=14.82 |type=concur |road={{jct|state=OH|SR|165|dir1=east|name1=Taggart Street}} |notes=Southern end of SR 165 concurrency }} {{OHint |township=Unity |ctdab=Columbiana |lspan=2 |mile=16.70 |type=concur |road={{jct|state=OH|SR|14|dir1=east|road|North Market Street}} |notes=Southern end of SR 14 concurrency }} {{OHint |mile=17.24 |type=concur |road={{jct|state=OH|SR|14|dir1=west|SR|165|dir2=west|road|Brookdale Avenue|city1=Columbiana}} |notes=Northern end of SR 14 / SR 165 concurrency }} {{OHint |county=Mahoning |cspan=8 |location=Petersburg |ctdab=Mahoning |lspan=2 |mile=21.23 |type=concur |road={{jct|state=OH|SR|617|dir1=west|name1=Garfield Road}} |notes=Southern end of SR 617 concurrency }} {{OHint |mile=21.32 |type=concur |road={{jct|state=OH|SR|617|dir1=east|CR|8|county2=Mahoning|name1=Youngstown-Pittsburgh Road|name2=East Garfield Road}} |notes=Northern end of SR 617 concurrency }} {{OHint |location=New Middletown |mile=26.04 |road={{jct|state=OH|SR|630|dir1=east|CR|30|county2=Mahoning|name2=East Calla Road}} |notes=Western terminus of SR 630 }} {{OHint |location=Poland |lspan=2 |mile=30.33 |road={{jct|state=OH|SR|616|dir1=north|name1=Water Street}} |notes=Southern terminus of SR 616 }} {{OHint |mile=30.39 |type= |road={{jct|state=OH|US|224|name1=Center Road}} }} {{OHint |location=Youngstown |lspan=3 |mile=33.55 |road={{jct|state=OH|I|680|city1=Youngstown|location2=Pittsburgh}} |notes=Exit 9 (I-680) }} {{OHint |mile=35.33 |road={{jct|state=OH|SR|7|name1=Market Street}} }} {{OHint |mile=36.64 |road={{jct|state=OH|US|62|name1=Canfield Road / Glenwood Avenue}} }} {{OHintbtm|keys=concur}}
==References== {{Attached KML}} {{Reflist}}
170 Category:Transportation in Columbiana County, Ohio Category:Transportation in Mahoning County, Ohio