Johannesburg - The SA National Roads Agency Limited on Sunday challenged Outa's claim that motorists are not buying e-tags.
“Sanral... is now sitting with more than 1.2 million e-tags that have been taken up,” spokesman Vusi Mona said in a statement.
Between 30 000 and 45 000 people were registering on Sanral's system each week, he claimed.
He said Sanral was thankful to those motorists who did not have e-tags but still paid for using tolled roads.
Mona questioned the Opposition to Urban Tolling Alliance's (Outa) research that motorists were not getting e-tags.
“We don't know who conducts their research or sampling and how credible their study is. Our figures, which like any aspect of our business, we report to Parliament such as we did last week, are not based on sampling, but on counting actual registered users.
“Also, ours are subject to being audited by the Auditor General. We don't know who audits Outa's,” said Mona.
He said the money collected would go towards road maintenance and paying off the debt incurred in building and upgrading Gauteng's freeways. Sanral claimed that since e-tags were introduced motorists had been enjoying less congested roads.