Stephen Joseph, chief executive of the Campaign for Better Transport, has welcomed the announcement of a trial of season tickets for part-time workers in London.
He is calling for the scheme to be introduced quickly and rolled out across the commuter network.
More top news
The 52-year-old had previous convictions for violence but was not on the anti-terror watchlist.
In a statement Charlton Athletic said: Keith was a true hero who will be greatly missed by all the Charlton family and everyone at the club.
London and the worlds has united on Twitter in defiance of the West minster attack #prayforlondon #wearenotafraid