[SOLVED] Question about roadblocks [Unstoppable Achievement]

Does anybody have an idea what is the easiest way to get a roadblock in police pursuits? I need to smash through 2 roadblocks in a single pursuit but so far I've only been able to smash through one in a pursuit,  since they seem to pretty rare, or I'm not looking in the right place.

Any help would be greatly appreciated as I really would love to continue the Outlaw side of the game!