It can be anticipated, as in old age or the onset of a killing disease. Death can also be sudden and unexpected. To recognize both, people throughout the ages have built tombs above and below the ground to bury their dead, and to preserve their memory with religious ceremony. The dead are still buried in cemeteries with gravesites adorned with tombstones as a monument to a life lived. Friends and family may also submit a picture of the deceased, with a written legacy in newspaper obituaries. The road memorial is different, however. It marks the spot where a sudden and unexpected death occured. People who erect these memorials find personal solace and closure, perhaps, by adding things that represent their connection to the one who died, or to show people passing by that this life was meaningful to somebody and is missed...