The main event takes place outside parliament in Westminster starting at 12.30pm, where 800 people are expected to attend, with another 200 at Holyrood in Edinburgh and 100 in Belfast.
Virtual lobbying is being held in Cardiff, with other protests expected at Belfast International, Birmingham, Bristol, Glasgow, Heathrow, Luton, Manchester and Southend airports.
In addition, a Twitterstorm will take place at 2pm using the hashtags #speakupfortravel and #traveldayofaction.