If you have a safe in your van, don't be complacent, use it.
Some interesting points having a read through these 26 pages.
My 2 penneth,
If you fear being robbed take a spare wallet/handbag and have it to hand with your normal ones out of the way.
Make sure they are filled with the normal stuff in them but make sure all the stuff is out of date, with a bit of change (old foreign coins are good for this) and a couple of fivers so if robbed they think they have won and won't come back.
Move on straight away and tell the police