"There was a bit of a change in measurement. What we've done is taken much more alternative routes into account, so that's why the results have shifted a bit, and what we have seen is Cape Town is the most congested city in South Africa than Johannesburg," Daan Hendrickx, regional manager for sub-Saharan Africa at TomTom, told CNBC Africa.
"When we look at the details, what you can see is that the congestion level on [Cape Town's] highways is much higher than in other cities. That brings up the overall congestion level, and that is probably the reason why it's now the most congested city in South Africa."
According to the report, Cape Town is ranked first with 27 per cent congestion, followed by Johannesburg with 25 per cent congestion and East London with 22 per cent congestion.
In Europe, the report indicates that Moscow is ranked first with 74 per cent congestion, followed by Turkey with 62 per cent and Palermo in Italy with 39 per cent.
"The idea of the report is if you want to tackle congestion, the first thing you need to know is where the congestion is. We can tell you where we have congested areas, and only then you can start working on a solution," Hendrickx explained.
"Traffic authorities can use these reports to actually re-design or re-look at the mobility plan of the city. Together with authorities, we want to see how we can improve the traffic flow in every single city."