Pennsylvania Avenue lighthearted celebrations, including a series of day- and nighttime Shriner's parades in the 1920s and 1930s. Thomas and Concepcion Picciotto are the founders of the White House Peace Vigil, the longest running anti-nuclear peace vigil in the US, at Lafayette Square on the 1600 block of Pennsylvania Avenue. After the Oklahoma City bombing in 1995, the Secret Service closed the portion of Pennsylvania Avenue in front of the White House to all vehicular traffic. Pedestrian and bicycle traffic, however, was still permitted on the sidewalk. After 9/11 this policy was made permanent. Near the White House traffic is redirected to
West Executive Avenue it intersects Pennsylvania Avenue, a portion of which was permanently closed to public traffic in 1995. One of several variants of a 1999 plan developed by the National Park Service envisaged the restoration of the historic and aesthetic qualities of the grounds surrounding the White House by converting West Executive Avenue into a pedestrian walkway and moving its parking inventory to a newly-built, below ground structure. West Executive Avenue was constructed in 1871, providing a first-time road link between the north and south sections of President's Park. According to the U.S. Government, in 1910 it was the scene of the