I also fall into the camp which opposes the closing off of waterways and railways by high security fencing. You cannot protect individuals from themselves or their own stupidity — which is what you are trying to do when you fence off railways and waterways. Logic says that every open unfenced road poses a far greater risk to lives, yet no one suggests we spend millions on security fencing and inconveniencing pedestrians and cyclists. All these arguments are well known and have been rehearsed a thousand times.
Nor is there nothing new in them. Back in the early-1970s when I was Birmingham city councillor there was a proposal to erect a security fence between canals and towpaths to reduce the number of people falling into the city's canals. This proposal was defeated, but a proposal to close off the city's rivers was successful despite opposition from a few councillors like myself. The River Tame was the northern boundary of the ward (Shard End) I represented and where I lived (Hodge Hill). Within weeks of the fence beingo erected I found teenagers with a acetylene torch removing a section of the metal fence so they could get to the river. In the summer kids were in the habit of fishing with nets for tiddlers or rods to catch small fish. Some built rafts and floated down the Tame. It was a river you could, except after bad rainstorms, stand up in. I did the same kind of thing as a kid in the 1950s. It was fun and I was well aware of the danger (in recent years I have walked parts of the River Erewash in the river itself).
Anyway, rant over, back to my map with thanks to osm-nottingham.org.uk. Click on the maps to enlarge.
*I am having open heart surgery sometime in January and plan to devote my post-op time to making a full recovery.