travel time should be counted/reimbursed in some form, the details would normally be in your contract. Do you have an employee handbook or anything? That would form part of your terms and conditions (regardless whether you have signed anything).
You shouldn't be working more than 48 hours in a week without having signed a Work Time Directive waver, but I'm not sure off the top of my head how travel time fits into that.
Essentially you are giving up time for which you are not being paid (directly). If you're happy with the amount of time you give vs salary received, then there's no problem really. But you are still giving up your weekends, unpaid, so you do have valid grounds to ask for some kind of recompense for that (extra holiday days? cash? whatever).