Protest marchers against e-tolling reached their second stop, at the department of transport in Pretoria, after 1pm on Friday.
They handed a memorandum to the department's acting deputy director general James Molao.
The Cosatu-led march swelled during the course of the day as people joined in off the city streets.
People sitting in cafeterias in the city began singing and dancing as protesters passed them.
"It is expected that the march will end at 14h00," city spokesperson Console Tleane said earlier.
At their first stop at the National Treasury around midday, Cosatu warned it would occupy "all the streets of Gauteng" on December 6 if it did not receive "positive" feedback on the anti-e-tolling memorandum by Monday.
"This action for today is just a warm up," Congress of SA Trade Unions provincial secretary Dumisani Dakile said.
"We must brace ourselves for a series of actions. We want a response by Monday 5pm... If they are not going to respond positively, we are going to occupy all the streets on 6 December."
Police blocked the Treasury entrance on Madiba Street while the crowd sang and danced as it delivered a memorandum of grievances.
It was received by Treasury official Huntly Pringle.
Pringle said they intended to consider it in "grave detail".
"We will do our very best to make sure you get a response by Monday."
The High Court in Pretoria on Wednesday reserved judgment on the future of the e-tolling system, following a challenge by the Opposition to Urban Tolling Alliance.
Dakile said the people would not accept the roll-out of the e-tolling project on roads between Johannesburg and Pretoria.
"The rich are getting richer and the poor are getting poorer. The public transport in this country is a mess."
Poor people paid a large part of their salaries to transport, said Dakile.
"This e-tolls is part of privatisation of our own roads. This system will benefit the elite in South Africa."
He said the next generation would be indebted by the tolling system.
"Voetsak (go away) e-tolls, voetsak," he shouted.