South Africa's poorest households are spending far too much of their disposable income on transport costs.

This is according to a Statistics South Africa (Stats SA) survey.

Public transport is considered affordable when commuters spend less than 10% of their disposable income on transport.

Statistician General Pali Lehohla says the study found two thirds of the country's lowest income earners used more than 20 percent of their disposable income on public transport.

The Money Show’s Bruce Whitfield interviewed Independent Transport Economist Andrew Marsay.

Marsay links the Stats SA survey with the e-toll system and says that poor people are on the losing end of our transport structure.

Scroll down for quotes from the audio below.

South Africa is unusual. Our apartheid legacy and low density is partly to blame.

— Andrew Marsay

People can’t afford to get to work late. And the cheapest forms of public transport - such as the railways - are unreliable. So people have to use minibus taxis.

— Andrew Marsay

Minibus taxis are the backbone of public transport in South Africa.

— Andrew Marsay

People prefer to use private cars. And most road users don’t want to pay for the roads. Do we put money on roads or public transport? Etolls was a mechanism to strike a balance but the relatively wealthy people in Gauteng are putting themselves first.

— Andrew Marsay