When you’re making purchasing decisions on a large scale one of the requirements you need to be clear on is:

Does the new acquisition suit the environment it will be operating in.

These requirements ought be stated in the contract of sale.

If the supplier makes claims that it does, and it turns out it doesn’t then they are in breach of the contract and can be tasked with making good.

Of course, sometimes we get these things wrong.

Agreed. But these decisions are being made by (and I must admit here I know nothing about the subject matter at hand, this is just speculation) almost certainly tens of thousands of municipalities across the country, independently. From small towns to big cities. From huge, organized departments that attend traffic signaling conferences, to folks who treat this component of their job as almost an afterthought. And we're only noticing the towns that screwed up, not the one that wisely chose NOT to implement LEDs for these reasons. Or the ones that made the calculated choice that, based on snowfall patters in their region, energy savings, savings on maintenance costs, vs the higher purchase price of the LEDs, that the LEDs were probably the right choice.

Thank you for the thoughtful response.