Link don’t work. At any rate, it doesn’t surprise me.
Here's the arguments from another site:
Opinions remain divided on the use and presence of roadside memorials in the United States and elsewhere. Obviously, the surviving family members and/or friends of the deceased support their creation and presence, but many people object to such homemade shrines for various reasons. Sometimes, the placement and/or size of a roadside memorial creates a legitimate hazard for motorists, who might find a memorial distracting or a visual traffic obstruction. Others object to the use of religious symbols on public property, considering it a violation of the constitutional principle of separating "church and state." Other people protest against roadside memorials purely on religious grounds, because such shrines can obstruct construction projects, or due to the fact that creating and/or maintaining roadside memorials can endanger human lives.
On the other hand, many people believe that roadside memorials serve a beneficial purpose, such as reminding motorists to slow down and/or drive carefully, or signaling that a particular stretch of roadway might be dangerous.
Still, others dismiss any objections altogether and argue that such spontaneous memorialization provides no greater distraction than the road signs and advertisements that are already littering our roads and highways.