Yes, of course... Gettysburg National Park is no diffrent than highlighting the spot where a drunk driver smashed into a wall or where a gangbanger got popped... whatever... the ill-designed,cheap,faded memorial is eye pollution to me... and another practice that other cultures have brought to this country...
Most are simply left there to rot, along with the trinkets and stuffed animals that were at one time fresh and new.
IMHO, if the family maintains the site in a tasteful manner, no problem.
Kind of like the "adopt a highway" program.
In the Seattle area, the city puts up signs that say "In memory of so and so. Please don't drink and drive".
Much more classy.
That little cross highlights the place where a dangerous stretch of road took a perfectly mannerly person who was caught in a storm and missed the danger in that stretch, it’s the place where a loved one zoned because of fatigue or road hypnotism, it’s the place where one was surprised by a bad driver, by an oncoming headlight on bright. Their loved ones highlight that place with a cross, and believe me, I note those places and they almost always reveal a danger, and some of them a very subtle danger.