To be honest walking, although longer may have been a good bet.
He can wear a baseball cap, hat, scarf to conceal his ID, he can duck into alleyways if anybody goes past etc. To be honest though this may be extreme.
Being out at that time of night if a police patrol car happened to drive past him he'd risk a pull over, walk bike or car. They will think he is out robbing.
Talking the brook house farm track.
Don't see it as " too tiring " as Adam says he would be determined 500k was at stake.