A hundred cyclists will be travelling from Swords Castle to Skerries from 10am this morning.
It is part of a campaign by Fingal County Council to make the roads safer for cyclists to use, and highlight the importance of drivers keeping a safe distance.
It recommends motorists leave 1.5 metres between themselves and cyclists, in an effort to reduce deaths and injuries.
There will be road signs in place throughout Fingal to raise awareness of the campaign and to encourage safe driving.