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.
Thousands of torch-bearers will form a kilometre-long river of fire during celebrations to mark the 50th anniversary of the Forth Road Bridge.