Pittsburgh and Pennsylvania Highways

PA 18

PA 18 starts at the West Virginia state line at the southern boundry of Pennsylvania, almost at the western corner of the state. (In West Virginia in 1999, it is marked as WV 69.) PA 18 runs north to New Freeport, then to Woodruff. At Rogersville, it intersects with PA 21, which is running between Waynesburg and Graysville. The two routes run together to Waynesburg.

At Waynesburg, PA 18 intersects with US 19 and PA 188. From Waynesburg, PA 18 runs northwest to Nineveh. From there, it runs north through Prosperity to Washington, where it crosses US 40 and PA 31 and intersects with US 19. From Washington, PA 18 continues north to Hickory, where it crosses PA 28 running between Bridgeville and Avella. From there, the route continues north to Florence, where it crosses US 22 running between North Star and Paris at the state line. PA 18 runs north to Frankfort Springs, where there is a junction with PA 931 from US 30 to the east and PA 168 from Glasgow to the north. PA 18 continues north to Service, where it first crosses US 30. At Service, PA 151 runs east to a junction with PA 51.

PA 18 continues north toward Rochester. Between Service and Monaca, PA 118 runs west to a junction with PA 168. In Rochester, PA 18 and PA 51 briefly run together and cross PA 68, which is running between Zelienople and Beaver.

Up to this point, little has changed since 1929. However, Service is now Mechanicsburg and PA 118 no longer exists as a state route. In Potter and Center Townships, as the route approaches Monaca, there have been changes to the roadway due to the Beaver Valley Expressway (PA 60) and a new four-lane road from the intersection of Broadhead Road into Monaca. There have also been changes in Rochester, where construction in the 1960s created a bypass around downtown (and moved PA 51 and PA 68 to a new bridge across the Beaver River).

PA 18 continues north to Beaver Falls, where there is a junction with PA 388. At Koppel, PA 451 runs to the west toward Enon Valley. At Wampum, there is a junction with PA 18 and PA 488 from Ellwood City to the east. North of Wampum, PA 930 takes off for a short distance to the east and PA 17 takes off to an intersection with PA 551 and the Ohio state line.

In New Castle, PA 18 crosses US 422 and intersects with PA 108 from Harlansburg to the east, PA 956 from the north, and PA 317 running to the west to the Ohio state line. PA 18 continues north to New Wilmington, where PA 158 runs northeast to Mercer and PA 278 takes off to the west before turning north to intersect with PA 18 again. At this junction, PA 318 runs west to intersect with PA 418, which continues to the Ohio state line. PA 418 runs north through Wheatland, crosses PA 518, and joins PA 18 in Hermitage. PA 518 runs between PA 18 and Sharon before swinging to the northeast north of Sharon to rejoin PA 18 just south of Clarksville. In Hermitage, PA 18 crosses PA 55, which runs from Mercer west to Sharon. North of Hermitage, PA 18 is joined by PA 518 before entering Clarksville, where there is a junction from the southeast with PA 258 from Mercer. PA 278 no longer exists as a route, but PA 318, PA 418, and PA 518 still exist in and around Sharon, although their exact routings may have changed. There is also a PA 718, which runs from PA 318 south of Sharon to north of Sharon, to the Ohio state line. PA 55 is now US 62.

North of Clarksville, PA 18 enters Greenville, where it crosses PA 58 running from Mercer to the southeast northwest to Jamestown. PA 358 runs west from Greenville to the Ohio State line. PA 18 continues north from Greenville along with PA 58. The routes split, with PA 58 running to Jamestown and PA 18 running to Hartstown, where it intersects with US 322 (running from Jamestown to the west). The two routes run together to Conneaut Lake. From there, PA 77 runs northwest to Linesville and the Ohio State line. US 322 continues east to Meadville, while PA 18 runs north to Harmonsburg and a junction with PA 618, which runs around the west side of Conneaut Lake to a junction with PA 77. PA 77 is now US 6 from the Ohio state line east to Meadville.

From Harmonsburg, PA 18 continues north to Conneautville and a junction with PA 198, which runs east to Hayfield and a junction with PA 98. From Conneautville, PA 18 runs north through Springboro and to Albion, where it intersects with PA 79. The two routes run east for a short distance, then PA 18 turns north to Girard, where it terminates at US 20. PA 79 is now US 6N. PA 18 now continues north from Girard through Lake City to terminate at PA 5 (previously PA 99).