I have tried googling this without success. Does anyone know of a compendium of vehicle limits in major cities in the world? For example, you can see here: NYC DOT - Motorists & Parking - Size and Weight Restrictions
that NYC has a limit of 55 feet except for articulated buses, which can be 65 feet. I also know that Paris has a limit for vehicles inside the city and I assume other cities do as well.
FWIW I do not recall any vehicle length limit posted anywhere I have been in Europe (there is sign provided for in legislation e.g. this German version but I do not recollect ever seeing it). Gross weight or height limits are pretty common, though.
In Germany the size limits are regulated in section 32 of the Strassenverkehrszulassungsordnung (§ 32 StVZO) - the largest possible length, for articulated buses and some kinds of truck-trailer combinations, being 18.75 m (59.05 ft)