There will then be a huge bridge party in South Queensferry with live music headlined by Scottish rockers Big Country and guests Bwani Junction.
The finale will be a fireworks display at 10:06pm in recognition of the bridge's 1,006m span.
Tickets for the procession and party, on 13 September, go on sale on Friday.
The event will end with a giant outdoor ceilidh, the "Forth Fling". There will be a free shuttle bus as there will be no local parking.
The procession is only open to over-16s. The party is open to under-16s if they are accompanied by an adult.
The bridge will close to all traffic in both directions at 22:00 for 30 minutes during the fireworks display.
Lesley Hinds, convener of the Forth Estuary Transport Authority, said: "The Forth Road Bridge was a huge engineering achievement for Scotland when it opened in 1964, and in the 50 years since it has provided fantastic service, carrying over double the weight and volume of traffic envisaged by the engineers who designed it. The bridge has transformed the economy of the east of Scotland and the lives of millions who now take crossing the Forth for granted.
"With the new Queensferry Crossing set to open in 2016, this is a pivotal moment in the history of the bridge."
Funding for the event has come from Homecoming Scotland, Edinburgh City Council and Fife Council.

The prosecution was brought by the RSPCA following a raid at a puppy farm at a traveller site in Essex.
Teresa Wade, 57, Victoria Montgomery, 54, her daughter Roxanne Montgomery, 33 and Tony Hammond, 34, admitted fraud at Basildon Crown Court.
The gang, from Essex and east London, will be sentenced later.
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All four admitted handling about 750 puppies between July 2013 and October 2014.
The court heard the animals were sold for an average of £450 each and the RSPCA estimates the fraud was worth more than £300,000.
The court was shown video footage shot by the RSPCA of dozens of cockerpoo (a cocker spaniel and poodle crossbreed) puppies kept in cages inside dark sheds near South Ockendon.
The dogs - some barely two weeks old - had soiled newspapers for bedding, no toys and some had no heating.
Teresa Wade, of Ship Lane, Aveley, South Ockendon, admitted advertising them over the internet as being home-reared, and that they were shown to prospective buyers at houses belonging to the other defendants, before being sold for up to £750 each in cash.
But some of the animals were so sick they died shortly after arriving at their new homes, or cost their new owners thousands of pounds in vet bills.
Wade will be sentenced later along with Victoria Montgomery, of Melford Avenue, Dagenham, and Hammond and Roxanne Montgomery, both of Grafton Raod, Dagenham.
Thousands of torch-bearers will form a kilometre-long river of fire during celebrations to mark the 50th anniversary of the Forth Road Bridge.
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Three women and a man have admitted fraud in connection with the sale of hundreds of puppies, some of which died or suffered serious health problems.