The Western England Rail Passenger's Committee has organised a series of meetings for passengers to discuss the South West Trains franchise.
This includes services between Bristol, Devon and London Waterloo, and is due for renewal in 2007.
The committee says it wants to know "what would encourage passengers to use the service more".
As well as the public meetings, commuters will also be interviewed on trains.
A spokesman for the committee said: "There is no substitute for contacting those people who actually use the service."
Anyone who misses this exercise can write directly to the passengers' committee in Bristol.
The process of deciding what the new franchise will look like starts later this year.