Not bad for a starting point! a few comments

It's awkward having the MPG and overall CO2 emissions on separate folds of the screen. I shouldn't need to scroll around to access ~10 numbers.

Also the UK is weird, we use MPG for fuel economy but will measure CO2 emission in kg.

Your transit calculator misses the opportunity to suggest a combined bike+rail trip which is the most practical.

Thanks @GrumpyNI, I'm currently in Amsterdam, you guys sure as hell have a lot of Teslas :) Happy we've hit the mark, although our calculations are based on estimations, we've done our best to keep it as relevant as possible.