This data is integral to the maintenance and growth of the parks, to environmental conservation, to gateway communities, and to our historical and sociological understanding. But the National Park visit data, like all data, is also approximate and imperfect. As we have seen, it is collected by imperfect devices, such as traffic counters that are vulnerable to weather or malfunctioning.
In a few of the paragraphs above, the authors detailed how traffic counters would break and remain in disrepair for a year or more.
Devices like the pneumatic tube traffic counter are not fundamentally complex, and are relatively cheap to maintain and replace. Think about the cost of a few thousand dollars at most and comparing that to the cost of some world famous national parks potentially being harmed due to some negligence.