A £100,000 system installed five years ago to divert traffic away from a busy Swansea road to stop it breaking European pollution levels could finally start working after a series of delays.
The Nowcaster will monitor air, traffic and weather, and send messages to signs in the city centre telling motorists to use other routes.
But the system on Neath Road has never worked because of software issues.
Swansea council said it will go ahead despite a new £5m relief road opening.
The Morfa distributor road, which runs parallel to the River Tawe, links Swansea city centre to the Liberty Stadium and was designed to help cut traffic on nearby Neath Road.
It opened on Friday, a year earlier than planned after £1.1m funding was received from the Welsh Government.
Mark Thomas, the council's cabinet member for environment services said: "It's definitely going to ease congestion on the road.
"But this road will not replace the Nowcaster system, it will complement it.
"It's still going to be able to read the airflow. It's going to be able to tell us the levels of pollution.
"We're confident that the [distributor] road will ease it on its own but that it's there as a back up and will be evidence-based."
Mr Thomas said the council has had assurances from the developers that the Nowcaster will be switched on in October, or by the end of the year at the latest.
But he said he was aware the last start date given was more than a year ago.
"We're as confident as we can be given the history of this. We've had funding for this project and we have to go ahead and complete that," he added.
"It absolutely will go ahead, it's just the timing has been the issue."