[This has annoyed me for years, but I’ve only just realised that I have to get the ranting over-and-done-with before the new bypass road is completed and opened and these signs are no more!]
The picture above depicts my “favourite” love-to-hate example of completely and utterly incorrect use of language on a road sign. It is one of about six or so instances of the same sign on the southward-bound approach to the Hunter River bridge at Hexham, on the outskirts of Newcastle.
My issue with this sign is the use of the word “both”. Essentially ALL online sources1 note that “both” means two out of two things in a group (of two). In this case then, where there are two lanes on the road in question, this sign is instructing drivers to use those two lanes simultaneously. In the vast majority of use-cases and for the majority of drivers, this action would be illegal!
The reasonable and grammatically correct alternate would be “either”, which is defined to mean one or the other of two things within a group of two.
But of course, if they had actually written that, I’d have no reason to whinge!