Security forces also used tear gas to disperse protesters in the northern city of Valencia and soldiers blocked the procession from reaching its intended destination.
In the capital Caracas, protesters' goal was to fill 25 kilometers (16 miles) of a key highway leading to the coastal state of Vargas.
About two hours after the caravan got under way, police on motorcycles fired tear gas to block the procession. The road eventually cleared.
Venezuela is mired in an economic crisis that has caused shortages of food, medicine and other basics in the oil-rich country. Protesters blame Maduro.
A total of 38 people have died in street unrest since protests first broke out on April 1. Hundreds more have been injured.
Elected in 2013, Maduro, the handpicked successor of the late long-time leftist firebrand Hugo Chavez, is resisting pressure for an early vote, calling the crisis the result of a US-backed conspiracy. His opponents have branded him a dictator.
Protesters also oppose his plans to elect an assembly -- and do it sidestepping the country's political parties -- to overhaul the constitution, dismissing it as a way to put off elections.
"You have to keep finding ways to protest," said Rafael Galvis, 46, as he drove a truck carrying a dozen protesters waving the red, blue and yellow Venezuelan flag and banners with slogans criticizing Maduro.
"We are going to stay in the street, building a way out of the crisis," opposition lawmaker Freddy Guevara told AFP as the Caracas rally got under way Saturday.
In the central state of Cojedes, groups of people riding horses joined the procession of protest.
'Just waiting for the day'
Pro-government people rallied in downtown Caracas to show support for the proposed 500 member constituent assembly that would rewrite the constitution.
Maduro stood by his plans in a speech Saturday.
"I am just waiting for the day that the National Electoral Council sets the date for electing the national constituent assembly so people can come out and do justice with their votes," Maduro said in a speech carried on state run TV.
He confirmed that at least half of the members would be chosen not by popular vote but rather by social sectors like blue collar workers and farmers -- which are heavily pro-government.
On Friday, demonstrators in the western city of San Cristobal held two police officers for 10 hours -- first encircling them at a rally and then keeping them in a house -- to demand the release of detained colleagues, citizens' ombudsman Tarek William Saab said.
He said they were released after he himself intervened.
The latest protests in Venezuela broke out when the Supreme Court issued rulings that stripped the opposition controlled National Assembly of its powers.
The court later backtracked amid an international outcry but protests resumed after Maduro called May 1 for creating a body to rewrite of the constitution.
Eyewitness? Submit your stories now via social or:
Email: news@pulselive.co.ke
