Johannesburg - The proposed Gauteng Freeway Improvement Project (GFIP) would result in "unmitigated" success and tangible benefits for South Africa, a public finance economist said on Tuesday.
"It will make the rich poorer, not the poor poorer," Roelof Botha told reporters in Johannesburg.
Botha's research found that the project would result in the highest income earning quintile (20% of the richest people) in Gauteng paying up to 94% of the toll fees, while most of the poor people would stick to public transport.
The Congress of SA Trade Unions had said recently that the project would make the poor poorer.
Botha, who spoke in his personal capacity and stressed he was not on anyone's payroll, argued that the flagship toll project would maintain South Africa's international credit ratings and obviate the need for fuel levy increases.
It would also allow rapid investment in road construction, alleviate traffic congestion, and enhance safety.
Last year, the SA National Roads Agency Limited (Sanral) announced that tolling was imminent on 185km of the N1, N3, N12 and R21 around Johannesburg and Tshwane.
In terms of GFIP, these roads and their interchanges had been improved and costs estimated at around R20bn would be recouped through toll charges.
Light motor vehicles are expected to be charged R0.40/km, medium vehicles R1/km, "longer" vehicles R2/km, and bikers R0.24/km.
Qualifying commuter taxis and buses would be exempted entirely.
E-tolling was placed on hold in January after a huge outcry that tolls were unaffordable.
Botha contended that commuting time saved (because of four lanes) would translate into productive earnings.
He was confident that the project would raise South Africa's international competitiveness.
"The GFIP funding model, approved by government as early as 2007, has assisted National Treasury in its attempts to maintain sound sovereign credit ratings during a difficult period (due to the 2008/2009 recession)," Botha said.
"It has also assisted Sanral in obtaining an international investor rating from Moody's."
He said an alternative funding through an increase in fuel price levy would, in practice, translate into funding from the country's general revenue pool and may increase the price of petrol by more than R1 per litre - which would have an inflationary effect on the economy.