The variable message signs (VMS), one of which is in Broadwater Road, Welwyn Garden City, are being introduced across Hertfordshire to offer real-time advice for drivers.
The cost of the scheme in is set to top £350,000.
Each notice costs around £12,000, plus £3,800 for installation.
The signposts will offer advice such as “don’t drink and drive, watch your speed, keep your distance and think bike.”
The council intends to rollout 10 in Welwyn Garden City, nine in Hatfield and four in Potters Bar, at a combined cost of £363,400.
Lib Dem councillor Malcolm Cowan, said: “It’s a Government grant, which sort of means we have to spend the money, if we don’t we’d have to return it.”
He added: “What we don’t want is for Welwyn Hatfield to be the only area that doesn’t have this technology.”
But Cllr Cowan said he believed the cash could be better spent.
“They are very expensive and the county council wouldn’t consult about the cost and give a say in where they went,” he said.
“I think there are infinitely better ways to spend that amount of money that means the total around the county will be around £3million – it seems an incredible amount of money,” he told the WHT.
Cllr Cowan also said some of the signs had been placed partially or fully obscured “behind existing trees”.
“It’s crazy,” he added.
Terry Douris, cabinet member for highways and transport, said: “We want to make the most of this technology for the benefit of all road users.
“Its primary role is to get traffic information messages to drivers at critical points on their journey and minimise congestion, and it is also a very effective way of encouraging drivers to think safety and be safe.”