Originally Posted by
thebigben
The Swiss have an interesting system for public transportation. You pay full fare by default, but you can buy a 50% discount for a year for $150. Thus, residents most often get this discount while tourists (usually) will pay full fare. Because the Swiss rail system is subsidized for about 50% of their budget by the taxpayer, this also makes it a relatively fair alternative.
Actually most tourists aren't paying full price either. The tourist half-fare card is about $120 for one month...there are several lengths of tourist nationwide rail passes plus a number of regional passes. The specific itinerary basically dictates which option is the greater savings. About the only time a tourist wouldn't find it economical to get the half-fare card or a pass, would be if they have extremely minimal and short train/bus/boat trips
Anyway, typically the biggest concerns with over-visitation are localized to specific sites. For example Machu Picchu has implemented measures to address overcrowding (though it's still very crowded) that includes ticket limits for the citadel and the two mountain hikes. Some sites with protected wildlife also restrict visitors.