Ballarat City Council will decide at a meeting tomorrow night whether to give in-principle support to the first stage of works, worth $1.5 million, to make Mair St the city's major east-west traffic route.

The works would include the removal of roundabouts in Mair St at the Dawson St and Grenville St intersections.

Both would be replaced by traffic lights, at a combined cost of $542,000.

Traffic lights along the length of Mair St would be sequenced for better traffic flow.

And extra turning lanes and more prominent signage would be put in at Sturt and Victoria streets.

According to a council officer's report, traffic surveys taken last year showed most drivers still used Sturt St, and Curtis and Little Bridge streets, when they travelled east or west through the city.

It said 60 per cent of east bound traffic without a CBD destination used Sturt and Curtis streets, while 81 per cent of west bound traffic went along Little Bridge and Sturt streets.

"This is likely due to the dual, divided nature of Sturt St, which presents a superficial impression that Sturt St remains the (major) traffic route, whereas Mair St is physically substandard for its arterial role,'' the report said.

Ballarat City Council development and infrastructure director Trevor McCullough said Mair St had been the major through road for the city since the Western Highway bypass in the late 1990s.

He said the plan was not about downgrading other streets.

"It's about upgrading Mair St to perform the function it was designed for as the highway through Ballarat," Mr McCullough said.