Interstate 66 is an interstate highway in the eastern United States. Its western terminus is at Middletown, Virginia at an intersection with Interstate 81; its eastern terminus is at Washington, D.C at an intersection with United States Highway 29.

Table of contents
1 Number of Miles
2 Major Cities Along the Route
3 Intersections with other Interstates
4 Spur Routes
5 Notes

Number of Miles

77

Major Cities Along the Route

Intersections with other Interstates

Spur Routes

None, although I-266 was planned in Washington, D.C., but was cancelled. It was cancelled due to environmental causes.

Notes

This is the only 2 digit Interstate to enter DC (unless you count the 100 yards or so that I-95 crosses over the DC section of the Potomac River at the Woodrow Wilson Bridge). I-66 used to intersect I-95, before they rerouted I-95 to be the east side of the Capitol Beltway.

The Department of Transportation has plans to extend I-66 westward across the country to California. Highway mavens have speculated as to where I-66 would go, such as the Corridor H Freeway in West Virginia and United States Highway 400 in Kansas.

President George W. Bush has written I-66 into law in Kentucky, with the routing being confirmed along the state's Daniel Boone and Louie B. Nunn (formerly Cumberland) Parkways.