What's your experience of reporting/collecting travel CO2 data

I am very interested to find out other CRAGs experience of gathering data on surface public transport (bus, train, tram, tube etc ) and car use.

The guidance notes for Big Green Challenge applicants specify frequent (daily or weekly) collection of travel data. So, I would like to know:

1. What data you ask for in your CRAG for both car and surface public transport
2. How often members are meant to report it
3. How well do you manage to report &/or collect this in practice
4. Anything you learned in this area e.g. best tools for calculating, how to raise compliance
5. If you are not already successfully collecting this data weekly, do you think your CRAG could manage it ?
6. How off-putting (if at all) do you think reporting this data weekly would be to potential recruits ?

At our last meeting, my CRAG agreed to report car mileage and surface public transport use weekly in line with BGC. For surface public transport we are counting regular travel (e.g. commuting ) and journeys outside a 50 mile radius of our home. We use The Carbon Account for car mileage. ( Users can ask CA to remind them weekly if they forget to input a reading.) I have asked my fellow CRAGgers to e-mail their surface public transport data to our group account because CA does not currently cover this.

Thanks