To dig your Cache hole in plain sight beside the road, you will probably need a few buddies (probably around 4 or 5 folks) dressed in High Vis Jackets and Hard Hats etc.
One to dig the hole with the pick and shovel.
One with a Clip Board with a pencil behind the ear.
One directing the first one with the pick and shovel where to dig.
One sitting in the driving seat in vehicle beside the hole having a nap.
One sitting in the passenger seat with a hot flask.
Take around 6 weeks to dig the hole, anything less will arouse suspicion,
Hope this helps.