{{Short description|State highway in Marion County, Ohio, US}} {{Use American English|date=April 2025}} {{Use mdy dates|date=January 2025}} {{Infobox road |state=OH |type=SR |route=423 |length_mi=17.09 |length_round=2 |length_ref=<ref name="sld">{{cite web |url=http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Documents/SLD/pdf_files/MARSR0423R.pdf |title=Technical Services Straight Line Diagrams - Route SR 423 |author=Ohio Department of Transportation |author-link=Ohio Department of Transportation |access-date=August 6, 2013}}</ref> |established=1969 |direction_a=South |terminus_a={{jct|state=OH|SR|47|SR|98}} in Waldo |junction= |direction_b=North |terminus_b={{jct|state=OH|US|23|SR|231}} near Morral |counties=Marion |previous_type=US |previous_route=422 |next_type=SR |next_route=424 }}
'''State Route 423''' ('''SR 423''') is a {{convert|17.07|mi|km|adj=on}} long north–south state highway in the central portion of the U.S. state of Ohio. The southern terminus of SR 423 is in Waldo at a T-intersection that also serves as the eastern terminus of SR 47, as well as the southern terminus of SR 98. The signed northern terminus of SR 423 is at its junction with SR 231 nearly {{convert|3|mi|km}} east of Morral. However, SR 423 is defined to continue northeast from this point along SR 231 for about {{convert|0.25|mi|km}} before coming to an end at the U.S. Route 23 (US 23) expressway.
In Marion, SR 423 and SR 4 form a concurrency and split into two one-way pairs. Northbound SR 4/423 travels on State Street<ref name=sld/> while southbound SR 4/423 (officially designated SR 4-D and SR 423-D<ref name=SLD423D>{{cite web |url=http://www.dot.state.oh.us/Divisions/Planning/TechServ/TIM/Documents/SLD/pdf_files/MARSR0423D.pdf |title=Technical Services Straight Line Diagrams - Route SR 423-D |author=Ohio Department of Transportation |access-date=August 6, 2013}}</ref>) travel on Prospect Street.
==History== The route that SR 423 currently takes was signed in 1923 as SR 4, between Waldo and Marion and SR 22 north of Marion.<ref name="ODOT1927_map">{{Ohio road map|year=1922|accessdate=September 12, 2013}}</ref><ref name="ODOT_1923">{{Ohio road map|year=1923|accessdate=September 12, 2013}}</ref> The entire highway became US 23 in 1926.<ref name="ODOT_1925">{{Ohio road map|year=1925|accessdate=September 12, 2013}}</ref><ref name="ODOT_1926">{{Ohio road map|year=1926|accessdate=September 12, 2013}}</ref> The route number was originally designated for a planned bypass around Portsmouth in the 1960s (now designated as Ohio State Route 823).<ref>{{cite news|url=https://www.newspapers.com/image/292406089/|title=State Lifts Barrett's Contract|agency=Associated Press|publisher=Chillicothe Gazette|date=April 10, 1963|page=1|via=newspapers.com|access-date=December 13, 2018}}</ref><ref>{{cite news|url=https://www.portsmouth-dailytimes.com/top-stories/33576/bypass-ribbon-cutting-is-thursday-road-to-open-friday|title=Bypass ribbon cutting is Thursday, road to open Friday|last=Corrigan|first=Tom|newspaper=Portsmouth Daily Times|date=December 11, 2018|access-date=December 13, 2018}}</ref> Between 1967 and 1969, US 23 was moved onto a new four-lane highway and the old route of US 23 became SR 423.<ref name="ODOT 1967">{{Ohio road map|year=1967|accessdate=September 12, 2013}}</ref><ref name="ODOT 1969">{{Ohio road map|year=1969|accessdate=September 12, 2013}}</ref>
==Major intersections== {{OHinttop|county=Marion|length_ref=<ref name="sld"/>}} {{OHint |location=Waldo |road={{Jct|state=OH|OH|47|OH|98|dir1=west|dir2=north}} |mile=0.00 |notes=Southern terminus of SR 423}} {{OHint |location=Marion |lspan=3 |mile=8.50 |road={{Jct|state=OH|OH|4|dir1=south}} |type=concur |notes=Southern end of SR 4 concurrency}} {{OHint |mile=8.89 |road={{Jct|state=OH|OH|739|dir1=south}} |notes=Northern terminus of SR 739}} {{OHint |mile=9.07 |road={{Jct|state=OH|OH|95|OH|309}}}} {{OHint |location=Bellaire Gardens |mile=11.37 |road={{Jct|state=OH|OH|4|dir1=north}} |type=concur |notes=Northern end of SR 4 concurrency}} {{OHint |township=Grand Prairie |ctdab=Marion |lspan=2 |mile=16.37 |road={{Jct|state=OH|OH|231|dir1=west}} |type=concur |notes=Southern end of SR 231 concurrency}} {{OHint |mile=16.66 |mile2=17.09 |road={{Jct|state=OH|US|23|OH|231|dir2=east}} |type=concur |notes=Northern end of SR 231 concurrency; northern terminus of SR 423}} {{OHintbtm|keys=concur}}
==References== {{Reflist}}
==External links== {{Attached KML|display=title,inline}} *[https://web.archive.org/web/20050503004236/http://www.state-ends.com/ohio/oh423/ State Route 423 Endpoint Photos]
423 Category:Transportation in Marion County, Ohio Category:U.S. Route 23