No trains were running on Southeastern, and the majority of the London Overground services were also stopped.
The AA issued an “amber alert”, warning that the train strikes will contribute to heavy road congestion at peak times, with more journeys expected due to sporting events and holiday getaways.
Aslef said rail workers had been left with little choice but to take action in defense of their living conditions.
Mick Whelan, the union’s general secretary, said: “Strikes are always the last resort. We don’t want to inconvenience passengers, our friends and families use public transport, too, and we don’t want to lose money by going on strike but we’ve been forced into this position by the companies, who say they have been driven to this by the Tory government.
“Many of our members, who were the men and women who moved key workers and goods around the country during the pandemic, have not had a pay rise since 2019.
“With inflation running at north of 10 per cent that means those drivers have had a real term pay cut over the last three years.”
He added: “We want an increase in line with the cost of living, we want to be able to buy, in 2022, what we could buy in 2021. It’s not unreasonable to ask your employer to make sure you’re not worse off for three years in a row.”