When I first started coming to the Lake District, several decades ago, the road to the southern lakes and beyond was a narrow road, only just wide enough for one lane each way. Then pressure of traffic led to parts of it being widened and some bits becoming dual carriageways. One of these bypassed the pretty village of Lindale, but then the road became narrow again as it wound through Low Newton and High Newton. A few years before I bought Limestone Cottage in Levens, the dual carriageway was extended by building the High and Low Newton Bypass. This has speeded up the journey considerably (until you get to the next narrow bit), but can’t have done much for the passing trade in the pub in High Newton.
Anyway, the reason for this rambling is that there is this ‘bridge to nowhere’ over part of this new bypass. This puzzled me for some time.
It is, apparently, a ‘bat bridge’. It is thought that bats navigate around their patch in the dark using their sonar to follow hedgerows or walls. Bats are reluctant to cross open spaces, due to the risk of predators, so removing linear features such as hedges and walls can restrict their commuting routes. When they do cross open areas they tend to do so low down – at vehicle height, with the inevitable fatal consequences.
Bat bridges like the one above are an attempt to mitigate these problems by providing a higher-level structure that the bats can detect and, hopefully, follow to cross the road. However in the years since structures like this have been built in various places in the UK, there is little evidence that they work – bats still cross open spaces lower down.
There is more on bat bridges here.