Simple enough. Best off grabbing an armoured truck as you’ll survive longer when people open fire on. If you miss, just keep driving, the risk of getting holy hell hammered into you whilst backing up/turning round is too great.
I’ve found the best roads to do this on are the ones marked on the map in yellow - there’s often a patrol walking along, in groups of three or four. The major roads (white on the map) have fewer foot patrols and more vehicles to contend with.