The Cosatu protests against higher fuel prices and VAT has ended and motorists are being allowed through the Marianhill toll plaza. Some had been stuck for hours.
One Twitter user said while she supported Cosatu's cause, she had missed a flight to Johannesburg because of the protests.
Police earlier fired stun grenades at protesting Cosatu members who ran onto the Pietermaritzburg-bound lanes at the Marianhill toll plaza and obstructed traffic, according to East Coast Radio.
Union leaders have reportedly called on them to intensify their protest action.
Supporters of Cosatu, South Africa's biggest trade union federation, on Friday morning marched to Mariannhill Toll Plaza on the N3 in KwaZulu-Natal to protest against the rising cost of fuel and an increase in VAT, IOL reported.
Motorists on the N3 took to Twitter to report long traffic backups on the N3.
Cosatu said in a statement on Thursday that the national campaign had received wide support from the public and social movements.
The union federation said problems facing South Africans were "man-made through the exploitation of men by men".
"The most daunting facts about the current increase in fuel and VAT are that‚ when it comes to expenses and the cost of living‚ the poor and the rich are expected to pay the same‚ while the share in the economy of the country remains unequal.
"Employers profusely refused to consider the cost of living in offering salary increases‚ including public sector workers who are government employees.
"Companies hardly resolved anything beyond 7%‚ with many workers still not paid bonuses or 13th cheques by their employers; mostly in the private sector‚" the statement read.
- FOLLOW News24 on Twitter