Venezuelans in cars and on motorcycles, bikes and even horseback clogged roads and police fired tear gas at them in another day of protest against President Nicolas Maduro.
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 25km of a key highway leading to the coastal state of Vargas.
But police on motorcycles fired tear gas to block the procession.
Venezuela is mired in an economic crisis that has caused shortages of food, medicine and other basics in the oil-rich country. Protesters blame Mr Maduro.
A total of 38 people have died in street unrest since protests first broke out on 1 April.
Elected in 2013, Mr 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.
In the central state of Cojedes, groups of people riding horses joined the procession of protest.
Pro-government crowds rallied in downtown Caracas to show support for the proposed constituent assembly that would rewrite the constitution.
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 Mr Maduro called for a rewrite of the constitution.
