In the days following a societal collapse, there will be some people who will be on the move from where the problems exist to where they hope safety lies. There can be many reasons why people are on the move, and an equal number of reasons why someone else may wish to stop your progress. Getting on the move and out of a hostile area as early as possible in the wake of a collapse is a significant key to one’s survival, as well has having buddies to cover you during your travel.
The sooner you get on the road, the less your chances of encountering problems. A few people will recognize the early signs of collapse and get moving out of town long before traffic becomes a problem. Others will recognize the issue within twenty-four hours after the event takes place, and will be on the leading edge of the traffic during the exodus. The majority will not realize the seriousness until it is too late. These people will get caught-up in the traffic jam that will rival the exodus of Houston during Hurricane Rita, where I-45 and I-10 were packed full of cars stopped on the highway for 100 miles. Many people ran out of gas on the side of the road and found themselves without food or water since they had only moved a few miles in four hours.
You may be a well prepared family, but for one reason or another are caught on your heals when a collapse occurs. This leads you to stay put longer than you would have liked, but you have no better tactical choices but to lay low at home or work for a few days before bugging out. You do not want to get caught in a highway traffic jam following a collapse. If you get stuck, you will have to leave most of what you packed into your vehicle(s) and move out on foot amongst the thousands of ill-prepared people on the roads doing things they would never have considered during normal times.
Those who are forced to wait out the initial exodus and are moving out of urban areas several days or weeks after the collapse will have a higher probability of coming in contact with an expedient ambush roadblock, both in the city and on rural roads outside of small towns. An expedient ambush roadblock is one set-up in haste with readily available materials and personnel. There will be plenty of desperate people who were caught unprepared for such an event; their lack of morals and innate nature to survive will drive them to take from others, with deadly force if necessary. It is your job to protect your family and yourself from these threats, especially when on the move.
While traveling in a vehicle on the roads, you may encounter various types of roadblocks or ambush points. Some may be fairly elaborate, while others may be quite simple. All are equally deadly. The primary tactic you will need to thread your way safely through one of these expedient ambush roadblocks is what I call R.O.C.S.: Recognition, Observation, Covering Fire, and Speed.
Recognizing that something you see ahead is a potential ambush site is the first key to success. An ambush site can appear as a traffic accident (as illustrated in Patriots), a fallen tree near or on the road, abandoned/broken down vehicles, anything blocking all or part of the road, detours, refugees, high ground on one or both sides of the road, bridges, and anything that looks like it does not belong on, or near, a road. These are the types of expedient ambush sites that someone may quickly create in the days following a societal collapse. It is up to whomever is leading, to recognize that a potential exists and to move into the observation phase.
Once you recognize a likely ambush point (LAP), you have two choices: divert your course and completely avoid the circumstance, or observe and evaluate the site. You can either stop well short of the potential ambush point and observe through a scope or binoculars, or have a passenger continue to observe while on the move. Observation is a form of Intel. Look for signs of movement, or things that seem out of place. Reverse what you see and put yourself in the place of the ambusher. Where would you hide? How would you set it up? How many people would you need to pull off an ambush? What weapons would you use? What tactics would you employ? What is your end game?
At this point, you need to determine if what you see is worth the risk of approach or if you need to turn around and find a different route (if possible). Anyone traveling with you should also evaluate the situation and help with risk assessment. Once a decision is made to approach and pass the observed site, cover[ing fire] is needed.
This is a two or more person/vehicle job. This means that if it is just you, your wife and the kids, that you need to move out of town in two vehicles. Hopefully you have friends traveling with you to a new location who also have a vehicle and weapons. For [overwatching] cover[ing fire] during the operation, the lead vehicle stops at a distance from the LAP that is within the range of the weapon being employed. For most weapon platforms a good distance is 100-300 yards. This ensures accurate shots and plenty of ballistic energy. The lead vehicle should place their vehicle at a 45-degree angle to the direction of travel and the weapon system should then be employed across the hood so that the engine block provides a [limited] ballistic shield for those person(s) providing cover[ing fire].
The trailing vehicles should move past the lead vehicle with Speed. Once beyond the LAP, those vehicles stop and provide cover for the other vehicle(s) yet to pass through the site. Again, the vehicles that have already passed the LAP should stop within range of the weapon(s) being employed and turn their vehicles 45-degrees to the road and take personal cover behind the engine, covering the passage of the trailing vehicles.
[JWR Adds: The concept of covering fire is actaully better termed suppressive fire. The term “cover”, properly, only applies to barriers that provide ballistic protection to those behind them. So “covering fire” does not provide cover, nor concealment, only supression!]
Passing through the LAP with adequate speed, and setting up a covering position on the far side for the trailing vehicles as fast as possible is key to minimizing exposure for all concerned. You do not want to drive so fast that you could lose control of your vehicle if you suddenly had to swerve or take significant evasive action.
Having short-range communications for these types of situations is also a smart idea. This can be done with CB  radios, or inexpensive GMRS /eXRS  two-way radios. Radios will be especially helpful during nighttime operations of this type. When the lead vehicle can communicate to trailing vehicle(s) that there is a LAP ahead, this can start a desired chain reaction that can significantly increase the odds of surviving one of these situations. Communications can also be an aid when the lead vehicle passes an unseen ambush point and can radio a warning to following vehicles, which can immediately render covering fire and/or take evasive actions.
The following is a fictitious scenario using all of the aforementioned, with three families in three vehicles approaching a potential ambush site seen from one mile away. The cars are traveling 200 yards apart. (After the SHTF , when traveling by foot or vehicle, travel should always be conducted in tactical columns, where a specified distance is maintained between people or vehicles. Staying too close together and/or tailgating are unacceptable risks after SHTF, when traveling.)
Lead vehicle (vehicle 1): “LAP ahead, one mile”
Trailing vehicles stop in place, while vehicle 1 moves forward another 1/2-mile and evaluates the LAP. The lead vehicle stops and uses 10×50 binoculars to scan the area. No movement is noticed, but it looks like a large tree was dropped across one lane of the highway. The base is obviously recently cut, and there are no other dead trees nearby. The leaves still have a greenish tint and have not yet browned, but are wilted.
Lead vehicle radios the trailing vehicles: “No movement seen, there is a way past the LAP on the opposite shoulder and grass. Watch the tree line on the right side of the road. Lots of dense cover there. We will move ahead to 200 yards and set-up.”
The lead vehicle approaches slowly to within 200 yards while the trailing vehicles move to within ½ mile away. The lead vehicle stops in the road and turns to 45-degrees to the direction of travel and both occupants exit the drivers side and set up across the hood with their AR-10  rifles with ACOG  scopes.
Lead vehicle radios the trailing vehicles: “Go!”
The first trailing vehicle (vehicle 2) gets up to speed and approaches the LAP while the lead vehicle continues to scan the LAP through their scopes, ready to fire upon any threat. The vehicle passes the LAP with no problems and goes 200 yards beyond and sets up an overwatch position on the other side, careful to orient themselves so as not to fire upon the vehicles on the other side. They are covering with scoped AR-10s scanning the LAP.
Vehicle 2 radios: “We are through and set up. Go!”
While vehicles 1 and 2 maintain covering positions, the last vehicle (vehicle 3) gets up to speed and starts to pass the LAP. As they do so, gunfire erupts from the tree line (in this instance, the ambushers were caught unaware by the first vehicle and were alert when the next one came through.) Vehicles 1 and 2 open fire on the tree line, while the passenger in vehicle 3 opens fire while passing the ambush. Once beyond the ambush point, vehicle 3 sets up 220 yards on the other side of the ambush to the rear and right of vehicle 2, and provides covering fire along with vehicle 2.
Vehicle 3 radios: “We’re set. Covering. No fire from the trees. Go!”
Vehicle 1 remounts and charges through the ambush point with no gunfire coming from the tree line. They drive beyond the other two vehicles and all personnel remount their vehicles and resume their travels.
At this point, it would be wise to find a secure place to stop and evaluate your persons and vehicles. You don’t need to stop all jumbled together, especially if there is more than one person per vehicle and everyone has a radio. Each vehicle stops a couple hundred yards apart and while one person provides cover, the other goes over the vehicle and passengers, looking for trouble.
You would want to check the tires, engine soft points (hoses, belts, etc.) and look for leaks (anti-freeze, fuel, oil, hydraulic fluid, etc.) Be sure to check each other carefully as adrenaline will be high and a person who has been shot or injured may not feel a wound at this point. Address any issues as quickly as possible and continue moving.
Stopping to evaluate and/or cover a position may not be advisable in some circumstances. You do the best you can at evaluating while on the move, radioing your findings to your travel companions, and then pushing through. This is where speed comes in to play. The faster you can get through the LAP the better your chances of survival. Your passenger (if you have one) helps with navigation, assessing threats, and provides cover during the encounter.
Choosing weapons is always a difficult decision, especially if you are going to be defending your life with them. For situations such as the one presented above, the longer the effective range of the weapon, the further away you can stay from the LAP, increasing your chances of survival. You must also consider that just because you can easily shoot a M1A  or even a .50 Barrett , your wife or teenager may not be able to adequately handle such a weapon in a life-or-death cover fire situation. [So a .223, 5.45×39, or 7.62x39mm rifle may be more apropos.]
Having a scope on your weapon will also increase your shot accuracy and your ability to observe the area for movement while your weapon system is employed. We all want to be accurate with open sights at long ranges, but if you are trying to hit the small exposed body part of a person behind cover at 250 meters, it is easier to find the body part to shoot at with a scope. People do not always present themselves as a nice squared-up silhouette like at a shooting range. When your target has taken cover, you may only get to see the top of a head, or part of an arm or leg. Putting a bullet in an extremity might not kill them, but it may take them out of the fight.
For night operations, having some form of night vision technology could become critical. These systems allow you to see through the darkness and into the darkest of shadows. Generation I systems are only adequate to about 50 meters and cost under $200. Generation I+ systems have a little more clarity and cost $300-500. Generation II and II+ systems can now be had for less than $1,000 new, and can be found cheaper from time to time in the used marketplace. These go up to $3,500 depending on features and manufacturer, and have a range from 100 to 200 meters with quite clear optics for the price. Generation III night vision has come down quite a bit and can be had for $3,500-$5,500. Personally, I cannot see enough difference between quality (with the exception of extended recognition range) of the Gen II and Gen III night vision to compel me to spend the extra $2,500+. There is also “Generation IV” night vision, which I know very little about. Prices seem to be in the $4,500-5,500 range. A Gen II, III, or IV night vision monocular could be a life saver, especially if you can get one that comes with an optional weapons mount.