The weight limit on the A507 between Baldock (the South Road roundabout) and Buntingford (the A10 roundabout) will come into operation on 28th August. This bans lorries over 7.5 tonnes from using the road unless they need to use it for accessing premised on or near the road.
“Unsuitable for HGV signs have been installed on roads leading off the A10, A505 and B197 which might be used by lorries avoiding the weight limit, along with signs directing which way they should be going.

Some of the signs are an unusual sort, without the usual words, like this:

Apparently this means the same as the worded version we are all used to, but of course not all drivers may be aware of this.