(18 Sep 2014, 8:45 pm)aureolin wrote Probably stipulated by Nexus, as I recall a previous contractor (possibly Interserve?) having Nexus logos on their fleet too.

It might have been DBL (Dowell Brothers) or even both.

Security companies (such as G4S, Security Plus, Loomis etc.,) also have similar arrangements with local authorities and business owners. This is why you see them parked up in pedestrianised or 'bus-only' areas like the Monument.