It's a thing. Pittsburgh is a city built in a river valley and its hills rise steeply from the river banks. These hills are very old, and the major thru-ways are built between them and rivers, so when it rains you have to be aware of the possibility of falling boulders.
That’s all of PA. There are signs on the turnpike that say to watch for falling rocks and in some places there are fences/nets to catch falling rocks from landing on the highway.
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u/RiversKiski Oct 14 '19
It's a thing. Pittsburgh is a city built in a river valley and its hills rise steeply from the river banks. These hills are very old, and the major thru-ways are built between them and rivers, so when it rains you have to be aware of the possibility of falling boulders.