Was talking to a mate on Friday who works for TFL (nice work if you can get it, they look after there own...).
He was asked to run his eye over a project another department are running:
They are concerned the new fixed ULEZ cameras will be vandalised, so-
They plan to rent a fleet of electric vans, big ones, fitted with ULEZ cameras, park them at certain locations to catch anyone with the cheek to drive their own car on certain roads, then put a bloke in each van to guard it!
Total cost about a million quid apparently...
Not working for TFL I was able to suggest a couple of real world money saving solutions:
Use smaller, therefore cheaper, electric vans!! Just put the camera on a pole on the roof if it needs to be up high, can't see why, numberplates are Normally visible from ground level

Or, slightly Tongue in cheek- buy a fleet of non ulez compliant vans, they're dirt cheap now for some reason!!, leave them just outside the boundary, save an absolute fortune on vans!

Or, and this is the most sensible-
HAVE THE BLOKES GUARDING THE MOBILE CAMERAS GUARD THE ORIGINAL FIXED CAMERAS!!!! No need for any vans full of cameras! Sorry that's just too simple isn't it, and saves a literal fortune, can't be having that.
No wonder every government goes over budget and over time ffs
To be fair to my mate he knows almost all TFL decisions are incompetent twaddle but he's not daft and knows which side his breads buttered. We do make sure to give him a hard time about his choice of career though