You are not on the clock (on duty) when you have submitted a valid leave pass. You are on leave. And if you are not on duty and you are injured you MAY not be covered by VA, depending on the situation.
If you are travelling on the queen's dime and she says that she will put you on a plane and get you there in a day and YOU choose not to take it, and instead choose to take your own vehicle, therefore requiring you to be away from your place of duty for more days that she had offered you to take then why should she pay for you to take extra days of travel and be away from work because of a choice you made. Gone are the swan days...long gone.
If you want to take your own way, take extra time to travel, then you will be reimbursed as per the offer she originally made to you (most economical means) and the extras and the onus are on you.
Why should the Canadian tax payer give you 2 extra days off because you want to drive instead of fly, or give you an extra 300$ for mileage over and above what a plane ticket would cost. Yes you must sign a waiver, in this office anyways, it simply states that you understand what I basically just told you, and if you don't want to sign it thats fine....then you don't go. Its all about choice...and for god sakes don't try to make the clerk behind the counter pay for your choices.
If you don't understand what the waiver is then it is your obligation to ask to have it explained to you before you sign, and it is my job and obligation to do so.
Its from the DCBA. If you want the ref I will give it to you.