Taxi-owners have complained that they will have to raise taxi fares to be able to afford to pay the new tolls.

Last week, the SA National Roads Agency Limited (Sanral) announced the tariffs for the 185-kilometre Gauteng Freeway Improvement Project.

Sanral CEO Nazir Alli said motorists who purchased the e-tag system would pay 49,5 cents a kilometre.

Medium-sized vehicles with the e-tag would be charged R1,49/km and heavy-duty vehicles with an e-tag R2,97/km.

Motorists would get further discounts depending when they used the highway and whether they were frequent users.

The tolling system drew widespread criticism, with concerns over its complexity and the effect on the economy expressed.

The Congress of SA Trade Unions in Gauteng said the tolling system would hit the poor and workers hard – given that workers already spent around 60 percent of their salaries on transport.

Provincial secretary Dumisa Dakile noted that there was no consultation with the federation or among the alliance partners on the system.

"We view such as an act in bad faith and we wish to place our position on record that as Cosatu in Gauteng rejects the imposition of the tolls in the province," he said in a statement.

The Democratic Alliance criticised the new tolling system as being far too complex to enforce.

"With the current billing chaos resulting mainly from the flawed Johannesburg computer system, not forgetting similar problems with the Ekurhuleni and Tshwane systems last year, yet another area of concern is being created with this system due to its complexity," DA Gauteng transport spokesperson Neil Campbell said in a statement.

"Taxes are meant to be transparent and simple to understand, and a toll is just another tax. This one however is so complicated that mistakes are bound to creep in," he said.

The Freedom Front Plus accused Sanral of being "dishonest" with the public about the tariffs.

At first it had said that the cost would be 50 c/km, but eventually announced a cost of 66 c/km.

"The Gauteng open tollgate tariff system is nothing other than an added tax," FF Plus parliamentary spokesperson Anton Alberts said in a statement.

He said the taxes on petrol should be used to cover the costs of road maintenance and upgrading.

Alli, on Monday in a brief telephonic interview, said the agency was merely implementing government policy.

He appealed to road users to take the benefits of the system into account. He said research showed that travelling on a good road reduced spending on the wear and tear of one's vehicle by a large percentage.

An awareness and education campaign was also underway to help people become accustomed to the system.

"My view is very simple, that [it's too complex] is what people say about any new technology that comes out. When people get used to the technology, it will become part of life," he said.