The Rail, Maritime and Transport union said Mr Crow's family have asked for the funeral service at the City of London Cemetery and Crematorium to be private but have invited trade unionists, friends and colleagues of Mr Crow to line the route of the funeral procession.
The procession will include trade union banners and flags and will end at the cemetery gates.
But the RMT executive said it hoped for a huge turnout at the annual May Day march in London to honour Mr Crow, who died earlier this month at the age of 52.
Mick Cash, the RMT's senior assistant general secretary, said Mr Crow's death had rocked the trade union movement, both in this country and around the world.
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Drivers belonging to the RMT union are due to walkout at 9.30pm on Saturday in a dispute over a sacked colleague.
A new opinion poll gives the party an increased lead at the expense of the Greens.
The Rail Minister said it was not a matter of crowd control but passengers "trying to get home after a long day at work".