Roadside memorials.

Are there too many of them? Do they distract drivers and cause more accidents, or do they prevent accidents by reminding you that your car is a death machine? If the latter, does that make them a morbid eyesore? Did you know you could order a memorial cross ready-made (with just the right handmade look)? Is there an Establishment Clause problem?

"For us, the memorials raise serious church-state constitutional concerns because they usually feature religious symbols and are placed on state property," said Robert R. Tiernan, a lawyer with the Freedom From Religion Foundation in Madison, Wis., who successfully defended a Denver man arrested in 2001 after he removed a religious roadside memorial.

"I'm sympathetic to people who have faced this kind of grief," added Mr. Tiernan, whose 13-year-old son died after a car accident in 1981. "But the public space belongs to everyone, and I think it's important to honor that."

Are these memorials an aesthetic blight? Some are tasteful and new or well-tended, but others are agonizingly awful -- mylar balloons! -- and covered in grime. But in some places tradition elevates them to a level that completely transforms my response:

[R]oadside memorials are most common in the American Southwest. Most researchers believe they descend from a Spanish tradition in which pallbearers left stones or crosses to mark where they rested as they carried a coffin by foot from the church to the cemetery. Because of this heritage, the memorials are protected in New Mexico as "traditional cultural properties" by the state's Historic Preservation Division.

Based on this, my preference is for some rules, not about religious imagery, but about size, placement, and materials that can be used. Allow only natural materials like stone and wood that have some historical tradition and that age and weather well even when abandoned.