British road signs use specially designed lettering, and much of it is quite distinctive. From the below link, you can download some of that lettering as a series of TrueType fonts.
Visit the roads.org.uk website and scroll down to the ’Pavement’ section. Here you can see what the fonts look like and download them. Remember that the taller characters are ’stretched’ [typically 900mm upwards].
This is, officially, the form used for painted lettering on the road surface — it's a vertically stretched version of Transport Medium. In real life, it's rarely used, as almost all lettering on the road surface in the UK is hand-painted. It contains a taller letter set for use on higher speed roads. This font file was produced by Nathaniel Porter.
