|Length||160.8 km (99.9 mi)|
|West end||Hwy 43 in Green Court|
|East end||Hwy 63 / Hwy 656 near Thorhild|
|Lac Ste. Anne County, Barrhead No. 11 County, Westlock County, Thorhild County|
|Provincial highways in Alberta
Alberta Provincial Highway No. 18, commonly referred to as Highway 18, is a 161-kilometre (100 mi) highway in Alberta, Canada. It stretches from Highway 43 at the hamlet of Green Court, through the towns of Barrhead and Westlock, to Highway 63 east of the hamlet of Thorhild.
Highway 18 begins northwest of the town of Mayerthorpe at the junction of Highway 43 at the hamlet of Green Court. It proceeds east for 8 km (5 mi), crossing the terminus of Highway 22 prior to reaching Highway 757. It turns north for a few kilometres and bends east again until it crosses Highway 764, then curves north again.
The jog in the road skirts Thunder Lake Provincial Park to the north. Upon reaching Highway 763, Highway 18 turns east to the Town of Barrhead where it meets Highway 33. The two highways run concurrently to the north for approximately 5 km (3 mi) until a T–intersection north of town. Highway 18 then turns east from this intersection while Highway 33 turns west. Highway 769 branches to the north towards Neerlandia, 2 km (1 mi) east of this intersection.
Highway 18 then crosses Highways 776 and 777 before it reaches Westlock at Highway 44, some 103 km (64 mi) from the starting point. It continues east, crossing Highway 2 at Clyde at an intersection known as "Clyde Corner". The highway goes through Thorhild as it crosses Highway 827 and proceeds west until it reaches Highways 63 and 656 where it ends.
Highway 18 originally was a connection between Highway 2 at Clyde Corner and the towns of Westlock and Barrhead. In the 1940s it was extended northwest from Barrhead to Fort Assiniboine, and then in 1960 to Swan Hills. In c. 1977, the 97 km (60 mi) section of Highway 18 between Barrhead and Swan Hills was renumbered to Highway 33, while Secondary Highway 655 between Barrhead and Thunder Lake Provincial Park, as well as Secondary Highway 656 between Clyde and Highway 46 (present-day Highway 63) west of Thorhild became part of Highway 18. Around the same time, gravel roads between Thunder Lake and Green Court were designated as Secondary Highway 918, and was upgraded and paved throughout the 1980s, becoming part of Highway 18 in c. 1987.
From west to east:
|Lac Ste. Anne County||Green Court||0.0||0.0||Hwy 43 – Whitecourt, Grande Prairie, Edmonton|
|||6.6||4.1||Hwy 22 south – Mayerthorpe|
|22.7||14.1||Hwy 757 south – Sangudo|
|Barrhead County||||43.7||27.2||Hwy 764 south – Cherhill||Hwy 18 turns north|
|Campsie||47.7||29.6||Hwy 763 north / PAR 107 west – Fort Assiniboine, Thunder Lake Provincial Park||Hwy 18 branches east|
|Barrhead||65.6||40.8||Hwy 33 south (49 Street) / 53 Avenue – Gunn, Edmonton||Hwy 18 branches north; west end of Hwy 33 concurrency|
|||68.9||42.8||Hwy 33 north – Swan Hills||Hwy 18 branches east; east end of Hwy 33 concurrency|
|70.5||43.8||Hwy 769 north – Neerlandia, Vega|
|Westlock County||||85.9||53.4||Hwy 776 north|
|89.9||55.9||Crosses the Pembina River|
|91.4||56.8||Hwy 777 south – Highridge|
|Westlock||106.3||66.1||Hwy 44 (104 Avenue) – Slave Lake, High Prairie, Edmonton|
|||117.7||73.1||Hwy 2 south – Edmonton||West end of Hwy 2 concurrency|
|Clyde||119.4||74.2||Hwy 2 north – Athabasca||Hwy 18 branches east; east end of Hwy 2 concurrency|
|Thorhild County||Thorhild||154.3||95.9||Hwy 827 (2nd Street)|
|||160.8||99.9|| Hwy 63 – Lac La Biche, Fort McMurray, Edmonton|
Hwy 656 east to Hwy 831
|Continues east as Hwy 656|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|