Re: Cost how much extra ?
That is the problem today, everybody claims about how insecure IT systems are, yet they want the cheapest possible components and software and won't pay even a penny for reasonable security.
Lighting is something that will be installed and remain in place for several decades (they have been updating our town - 30,000 residents, so not overly large - with new street lighting for about 5 years now, I'm not sure how much longer it will take, but I'm guessing another couple of years. Many of the lights being replaced are from the 1970s or earlier. They have done small upgrades over the years - as bulbs blew, they were replaced by energy saving bulbs and the new lamp posts use LEDs.
So the recoup on investment of 1p per lamp post over the amortization of a street lighting system is nothing. Although it would probably add a few hundred Euros to the price of the complete project, but again, chicken feed.
Towns and cities just don't have the budget to replace such systems on a biannual basis, so if they are going to use a smart system, it needs to be robust and secure, if it is going to last a couple of decades, before it can be upgraded again.