The numbers surpassed both organisers' and the police's expectations. Around 2,700 people had joined a Facebook event for the demonstration.
Demonstration organisers described the event as a "small popular rebellion”, saying politicians are showing contempt towards voters by planning to go ahead with the congestion-charge scheme despite 57 per cent of residents voting against it in a referendum.
"Politicians don't listen anymore. They should have taken the opportunity to create a proper citizen dialogue where everyone takes part and where we all feel like building something completely new in this city," Barbara Lindell, a spokeswoman for the newly formed group Västsvenska Folkinitiativet (The Western Sweden People's Initiative), told news agency TT.
Demonstrators shouted slogans and carried signs and banners with lines like "Respect the referendum" and "57 percent can't be wrong".
Eva Smedberg, another organiser, said the demonstration brought people from rivalling political camps together.
"Today, we have forgotten about our political colours and we stand here to save our city," Smedberg said to rapturous applauds.
Demonstration organisers also said they oppose plans to build a train tunnel called Västlänken, which would be partially financed through congestion fees. Opponents of the train tunnel project cite high costs and the long construction time as the main drawbacks.
Work on the tunnel, which is designed for commuter trains and regional trains, is due to start in 2018 and trains could start operating in 2026. According to the Swedish Transport Administration, the budget for the project is SEK 20 billion.
The congestion charge was introduced in 2013 in order to finance a large infrastructure project called the western Swedish package, which the Västlänken tunnel is part of. After a campaign in the local newspaper GT collected enough signatures for a so-called people's initiative, the city council decided to call for a referendum.
The referendum was held in September and 57 percent voted no to the congestion charge. However, local and regional investors in the infrastructure project decided to keep the charge.