Portal:U.S. roads/Did you know/June 2010

...that although Donner Pass (pictured) has historically carried the First Transcontinental Railroad, Lincoln Highway, Victory Highway and California Trail across the Sierra Nevadas, the planners of the Interstate Highway system instead decided to route Interstate 80 across a higher summit 2 miles (3.2 km) to the north?
...that while traversing mountainous terrain, Interstate 5 in California has a portion where traffic in one direction crosses over the traffic lanes for the other direction?
...that the Harbor Tunnel Thruway, otherwise known as Interstate 895 in Maryland, has had three different sets of exit numbers?
...that construction of Interstate 140 outside Wilmington, North Carolina was delayed in part to redesign an off-ramp to avoid a 450-year-old oak?
...that prior to Interstate 410 and the Interstate Highway System, Texas State Highway Loop 13 was the primary loop around San Antonio?