Bolsonaro political allies, including his chief of staff Ciro Nogueira, have already begun to establish contact with the Lula camp to discuss a transition. Some, including the speaker of the lower house of Congress, have publicly said the Bolsonaro government should respect the election result.
The president's election concession may defuse protests by his supporters who have blocked highways in many states across Brazil, along with pro-Bolsonaro truckers calling for him to defy the electoral victory of leftist Luiz Inacio Lula da Silva.
Earlier Tuesday, Justice Alexandre de Moraes called on the Federal Highway Police [PRF] to remove all the blockades, which have been mainly organized by truckers, a core constituency of the Bolsonaro government's support.
Moraes was quickly joined by six other justices in a virtual session in the early hours of Tuesday as they formed a majority in the 11-member court to back his decision, setting fines on the PRF's director-general Silvinei Vasques if he failed to act to clear the roadblocks.
The Supreme Court's action opened access to a key grains-exporting port, while the protest shut off the country's largest airport started to affect the transportation of food and fuel.
The PRF said truckers had blocked highways at 271 points, partially or fully, as part of protests that have spread to 23 of Brazil's 26 states in the wake of Bolsonaro's loss to Luiz Inacio Lula da Silva in a runoff election on Sunday.
Lula's win represents a stunning comeback for the 77-year-old former metalworker, who governed Brazil from 2003 to 2010 but then spent time in prison for corruption convictions that were later annulled.
Lula has vowed to overturn many of Bolsonaro's policies, including pro-gun measures and weak protection of the Amazon rainforest.
However, some truckers posted videos calling for a military coup to stop Lula, a leftist who served as Brazil's president from 2003 to 2010, from taking office.