Paris metro workers walked off the job Friday over plans for a major overhaul of the pension system, sparking huge traffic jams as commuters scrambled to find other ways of getting to work.
Ten of the city's 16 metro lines were shut down completely, while service on most others was "extremely disrupted," the city's RATP transit operator said.
Massive crowds waited on the platforms of the two automated driverless lines still operating and officials counted nearly 300 kilometres (185 miles) of traffic backups during the morning rush hour, more than double normal levels.
Two of the three main suburban lines that traverse the city were also severely disrupted, as were most bus and tram services.
But with many workers taking the day off, or managing to find alternative travel solutions, from bikes to electric scooters, skateboards and unicycles, the situation was not as chaotic as many had feared.
"We had expected a lot more people," an RATP agent at a station on Line 1, a fully automated metro that runs east-west through the heart of Paris, told AFP.
"Lots of my colleagues organised things so they could stay home. For example we had a meeting today that we pushed back to next week," said Gwenn, a 39-year-old financial controller, at the Bastille station.
To help ease the gridlock, the RATP offered free 30-minute rides on the Cityscoot network of electric mopeds.
US ride-hailing giant Uber is also hoping to seize the moment with two free 15-minute rides offered on its Parisian fleet of electric bikes and scooters.
'Shot across the bow'
The strike is the first major protest against President Emmanuel Macron's plan to implement a universal pension system that would do away with the more advantageous plans enjoyed by workers in state transport and utility companies.
Other professions that have special schemes include sailors, solicitors and Paris Opera workers.
Metro workers say the reforms would force them to work longer by removing their long-held rights to early retirement, secured decades ago to compensate for spending long hours underground.
France's state auditor, the Cour des Comptes, said the average retirement age for RATP workers in 2017 was 55.7, compared with 63 years for most French workers.
The three main RATP labour unions have called the strike "a shot across the bow" against the overhaul, the latest element in Macron's push to bolster France's economy and cut spending.
"It's not a strike by the privileged few. It's a strike by employees saying 'We want to retire at a reasonable age with a reasonable pension'," Philippe Martinez, head of the CGT union, told France Info radio.
It is shaping up to be the biggest metro strike since 2007, when former president Nicolas Sarkozy also pushed through pension reforms.
During his 2017 presidential campaign, Macron pledged not to touch the current earliest legal retirement age of 62 for most workers.
The reforms unveiled in July, which would harmonise the 42 different pension schemes currently in place, would still allow people to retire at 62, but on a reduced pension.
A full pension would only be available from 64.
The government is in negotiations with unions over the reforms, which are likely to face further opposition in the coming weeks.
Lawyers, airline pilots, stewards and medical workers have already called a strike for Monday.