X-height.

Which is the size specified for lettering on road signs. This is unusually large for cycle route signage but it is, probably, right for the motorists given the class of road. I'm no expert in the rather gripping Traffic Signs Regulations and General Directions 2016. 

In the extra there's a non-standard sign, but it is off-highway, which I didn't follow! It is possible to bunny hop a Brompton...

A wonderful day out in the sunshine looking at some routes, in fact it was so nice that after riding from Rugby to Leamington I rode back again rather than catching the train. All made possible by one of our smashing volunteers who refuelled me with cake and tea and Electric Eric with some solar generated electricity. Perfect! A lovely day out in the sunshine all powered by sunshine.

42 miles in total, which would have been achievable on the one charge but since I had the fast charger with me I was able to fill up and blast back to Rugby on level 3.