Sgt. Curt S. Mowers, Minnesota State Patrol says the following:
““ROAD CLOSED TO THRU TRAFFIC” or “LOCAL TRAFFIC ONLY” tells you that you NEED to take a different route and should only cross the barrier if you have no other option to reach your destination within the restricted area. For example, if the driveway to your home, worksite, a friend or relative’s home can only be accessed on the restricted roadway you are LOCAL TRAFFIC and NOT THRU TRAFFIC. If your destination is outside the restricted area, you must take another route and not go THRU.
“ROAD CLOSED” means just that; you cannot enter or cross the barrier; if you try you may not get through, you may damage road work, get stuck and/or be subject to a citation. MNDOT explained that it would not typically put up a ROAD CLOSED if access was needed. Even emergency vehicles generally have to re-route around a closed road.
MNDOT “DETOUR” routes use paved roads, which can handle the weight of the detoured traffic while not violating load restrictions, and they focus on the shortest and most direct route. For those thinking they know better than MNDOT keep in mind that if you stray from the detour odds are great you will arrive at a dead end, get stuck on gravel roads, get lost, and travel further. When drivers go off detours MNDOT and the State Patrol begin getting complaints about the unusual traffic, vehicles using driveways to turn around and people requesting directions.
“TRAFFIC CONTROL CHANGE AHEAD” warnings are placed in advance of to a change in traffic control devices. For instance, if stoplights were removed or stop signs are added, deleted, or set up differently. These signs are important to heed, as you do not want to go through an intersection assuming the traffic control is the same – a habitual response to these intersections or road changes could be tragic.
It is a violation and a citation can be written if you violate these lawful directions. Fines can be over $100. If winter and you cross a barrier or gate to access a winter storm closed roadway you will be in for a fine and a bill if you need to be rescued - up to $10,000.
MNDOT seriously considers what signs to put up and where - you can trust that they have done their homework and it is in the driver’s best interest to regard posted signs.”