Interstate 40 (I-40) is an Interstate Highway in Oklahoma that runs across the state from Texas to Arkansas. West of Oklahoma City, it parallels and replaces old U.S. Highway 66 (US-66), and, east of Oklahoma City, it parallels US-62, US-266, and US-64. I-40 is the longest Interstate highway in Oklahoma. Cities along the route include Erick, Sayre, Elk City, Clinton, Weatherford, Oklahoma City and its suburbs (El Reno, Yukon, Del City, and Midwest City), Shawnee, Okemah, Henryetta, Checotah, and Sallisaw. Route description I-40 enters Oklahoma near Texola in Beckham County. It crosses the North Fork of the Red River near Sayre and runs through southern Elk City. It then cuts across northwest Washita County before entering Custer County. There, it passes through Clinton and Weatherford. After leaving Weatherford, I-40 then runs across northern Caddo County. After that, it enters the Oklahoma City metropolitan area at Canadian County. I-40 runs through the southside of El Reno as it enters the Oklahoma City metropolitan area. It then passes through Yukon before entering Oklahoma City city limits. In west Oklahoma City, I-40 has a junction with I-44. It then runs just south of downtown Oklahoma City on a new 10-lane section. I-40 then interlines with I-35 at the Dallas Junction complex. This forms a concurrency with it for . After the Dallas Junction, I-40 then passes through Del City and Midwest City on the Tinker Diagonal. This provides access to Tinker Air Force Base in east Oklahoma City. In far eastern Oklahoma City, I-40 meets I-240 in a partial junction. Afterward, it passes through the northside of Shawnee. This marks the eastern end of the Oklahoma City metropolitan area. In Henryetta, I-40 serves as the northern terminus of the Indian Nation Turnpike. In McIntosh County, it crosses the northernmost arm of Lake Eufaula. Afterward, it meets US-69 south of Checotah. Near Webbers Falls, I-40 is the southern terminus of the Muskogee Turnpike. It then crosses the Arkansas River before passing through southern Sallisaw. The Interstate crosses into Arkansas north of Moffett. History West of Oklahoma City, I-40 parallels and replaces Old US-66. US-66 was decommissioned in Oklahoma in 1985. Bridge collapse The I-40 bridge over the McClellan–Kerr Arkansas River Navigation System near Webbers Falls was struck by a barge on May 26, 2002, causing the bridge to collapse and resulting in the death of 14 people. Westbound I-40 traffic was detoured through Gore