Collision Prevention

by | Oct 31, 2019 | Collision

Collision Prevention

Driving includes a few tasks: controlling the car, watching the road for other drivers, hazards and understanding the signs and signals to make decisions. You need to drive defensively to protect yourself and prevent collisions.


Your vision is crucial for driving and it’s very dangerous for everyone if you’re not looking at where you’re driving and at the obstacles around you. You can avoid this by constantly scanning the road for hazards and other vehicles. One of the most popular methods is the Smith System of SIPDE. This refers to:

  • Search – search the roadway and the off-road area 20 -30 seconds (about a block to a block and a half) ahead for information that can help you plan your path of travel. Use a systematic search pattern to gather information. First search the road ahead, then to the sides, then glance in your rearview and side mirrors.
  • Identify – Locate hazards and potential conflicts. Other vehicles may move into your path and increase the likelihood of a crash, pedestrians and animals are unpredictable and stationary objects will influence your driving strategy
  • Predict – Consider speed, distance, and direction of hazards to anticipate how they may affect you. Cars moving into your path may influence your driving strategy
  • Decide – based on your prediction, decide what you need to do if the situation changes quickly. You need to be making constant decisions to cope with the changing traffic.
  • Execute – The final step is to execute the decision you have made. In most instances, executing a decision simply means making a routine maneuver.[1]

When scanning the road, look at least 15-20 seconds ahead (about two blocks in the city or 1/3 mile on the freeway). If you don’t look far enough ahead, you will overlook any hazards that may be coming your way. Also, check the vehicles behind you every 5-7 seconds.

Escape Route

You must constantly adjust as traffic conditions evolve to avoid dangerous situations. Scanning ahead helps to ensure your path of travel is safe and allows you to spot potential hazards ahead of you to adjust your speed. Slow down if your view ahead is blocked because you will not be able to adjust otherwise. When changing lanes, look for a wide enough gap to maneuver into without forcing others to slow down.

When scanning the road, watch for hazards or indications of hazards such as car slowing down, lane blockages or vehicles suddenly going faster or slower. These can happen at any time so you’ll need to be able to predict what may happen. If there’s a long line of cars approaching from the opposite direction, you will need to slow down and be prepared to brake and move to the right. When approaching a curve, slow down before entering and stay towards the right of the lane. [2]

Blind Spots

You need to check your blind spots and avoid lingering in other driver’s blind spots. Blind spots are shown in the picture below.

Vehicles can be completely overlooked if they are in your blind spot and it is especially easy to overlook motorcycles. You can use your rear-view mirror and side mirrors to check your blind spots by scanning every 5-8 seconds and when you want to change lanes. This will help you adjust to the ever-changing traffic conditions. You need to turn your head in order to see in your blind spots because the mirrors cannot see into the blind spots. There is some newer vehicle with blind spot alerts built into your side mirror but it is still good practice to check your blind spots by turning your head.

Make sure your mirrors are positioned correctly if you are checking them. If positioned correctly, it will account for most of your blind spots. Your mirrors must be set from your normal position on the driver’s seat. [3]

Backing Up

Blind spots are an issue when backing up. There may be debris to the rear that can damage your car or a passing vehicle or young children may be behind your vehicle. According to KidsAndCars.org, every week there are 50 children backed over in the US because a driver could not see them. Over 60% of the back overs involved large vehicles (truck, van, SUV). Most drivers are unaware of the large and dangerous blind zone that’s behind their vehicles and children do not understand the dangers of slow-moving vehicles. Majority of the back over victims are one year old and children younger than 5 are most at risk. An average of 232 fatalities and 13000 injuries occur every year due to back overs.

Drivers can heighten their awareness before engaging a vehicle in reverse especially when children are present. Young children are impulsive and unpredictable and have a very poor judgment of danger. Safety/Prevention Tips include:

  • Always walk around and behind a vehicle prior to moving it.
  • Know where your children are. Make sure they move away from your vehicle to a place where they are in full view before moving the car. Verify that another adult is directly supervising children before moving your vehicle.
  • Install a rearview camera, backup sensors and/or additional mirrors on your vehicles. Use these devices in addition to looking around and behind your vehicle carefully to detect if anything is in your path before backing.
  • Make sure children hold hands with an adult in parking lots at ALL times. If you have multiple children and not enough hands, create a hand-holding train or fasten the younger children into a stroller and make sure everyone stays together.
  • Teach children that “parked” vehicles might move and make sure they understand that the driver might not be able to see them, even if they can see the driver.
  • Teach your children never to play in, around or behind a vehicle. The driveway is not a safe place to play.
  • If you have an adult passenger with you, ask them to stand outside the vehicle and watch for children or animals as you back out. Ensure they are a safe distance away from the vehicle so that they are not in any danger.
  • Be aware that steep inclines and large SUV’s, vans, and trucks can add to the difficulty of seeing behind a vehicle.
  • Keep toys, bikes and other sports equipment out of the driveway.
  • Trim landscaping around the driveway to ensure drivers can see the sidewalk, street, and pedestrians clearly when backing out of their driveway. Pedestrians also need to be able to see a vehicle pulling out of the driveway.
  • Install extra locks on doors inside the home high enough so children cannot reach them and toddlers cannot slip outside on their own.
  • Roll down the driver’s side window when backing so you can hear if someone is warning you to stop.
  • Be especially careful about keeping children safe in and around cars during busy times, schedule changes and periods of crisis or holidays.

Following Distance

Maintain a space cushion around your vehicle and increase your following distance if you want to avoid crashes. Scanning ahead will help you to know if it is safe for you to move into a lane or your left or right. You’ll need a large cushion at higher speeds so always try to maintain a 2-second rule. This rule refers to how much time ahead of you is needed for a safe distance cushion. This is the minimum recommended following distance. To establish a 2-second rule, pick an object on the side of the road such as a tree or a sign and wait for the vehicle in front of you to pass that point and count “one-thousand-one, one-thousand-two”. If you pass that point before you finish counting then you are following too closely. You may need to establish a 3 second or 4-second following distance under the following situations:

  • You’re being tailgated
  • Your vision of the rod is obstructed or visibility is poor
  • You are behind a large vehicle and can only see the vehicles back and not the road.
  • You are driving on slippery roads such as ice or snow
  • When following a motorcycle
  • The driver behind you wants to pass
  • You are following a bus or school bus that makes frequent stops
  • Road or weather conditions are poor
  • Travelling at high speeds
  • Pulling a trailer or carrying a heavy load
  • Merging onto a freeway

To ensure you establish a safe following distance, make sure you look ahead and around your vehicle as well as the one ahead of you. Check your mirrors, speed, and the road regularly. [4]

Avoid Being Rear Ended

A rear-end collision is common at intersections but may also result from tailgating. It’s no fun to get into an accident and rear-end collisions are always preventable. If you are following these 10 tips, then you can greatly reduce your chance of getting into a rear-end accident.

  1. Look down the road to spot any stopping traffic long before you need to step on your brakes. This will allow you to brake early and slowly so the vehicle behind will brake sooner as well.
  2. Mirrors need to be constantly checked every 5 – 10 seconds. When you approach a stop sign or a red light, make sure you check your rear-view mirror to ensure the vehicles behind you are stopping. You should also check your rear-view mirror when traffic is slowing down on the freeway.
  3. Always stay focused on your driving as there may not be vehicles behind you when you initially stopped but they could be rushing up behind you as you are waiting. Drivers are distracted by a lot of different things nowadays such as cell phones and the other high tech stuff in their vehicle.
  1. Always have an escape route in mind when you’re slowing down. Escape routes can be shoulders, sidewalks, curb lanes, left turn lanes or anywhere safe you can get out of the way of another vehicle.
  2. Always slow down gradually when pulling up to a stop sign or red light. When you slow down gradually, the vehicle behind you will also slow down gradually. If you brake suddenly then the vehicle behind may not be able to react in time to your sudden braking.
  3. When you stop, make sure to leave two to three car lengths between you and the vehicle in front. If you are too close to the vehicle in front, you have locked yourself into a potential danger zone which eliminates your escape options. If a vehicle hits you from behind, you may be pushed into the vehicle in front and you will be at fault.
  4. Check your brake lights frequently to make sure none of them are blown. If one of your brake lights are out, then it can affect the drivers behind you from knowing when you are decelerating or trying to stop.
  5. Leave enough space between you and the vehicle in front of you. If you follow too closely, then you increase the chance of hitting the vehicle in front of you. It also forces you to brake harder which will cause vehicles behind you to brake rapidly increasing the chance of a collision.
  6. If a vehicle follows too closely, don’t brake hard to try to scare them off because you can be involved in a rear-end accident. You should slow down gradually and let them pass instead. [5]

Stopping Distance

The stopping distance is dependant on the speed you travel. The greater your speed, the longer it’ll take to stop. Other factors that affect stopping distance include rain or snow, and slick on the road and how worn out your brakes and tires are. The 3 factors that influence your total stopping distance are perception, reaction time and braking.

Your perception time is the time it takes for you to see and recognize a hazard. During ideal conditions, it will take an average driver 0.75 seconds to perceive danger. If you’re traveling at 40 mph or 60ft per second, you will have traveled 45 feet in 0.75 seconds. The distance you’ve traveled before you perceive a potential danger is called your perception distance. Your vision and level of alertness will also affect your perception time. For example: if you’re texting and driving, your perception distance will be much greater and your chances of getting into an accident will be higher.

Braking distance is the distance it takes for your vehicle to stop after you press the brake pedal. The condition of the brakes, tires, weight of vehicle and road condition will affect your braking distance. For example, at 40 mph, it can take your vehicle 72 feet to stop after applying the brakes, when you double your speed to 80 mph, it will take you 288 feet to stop after applying the brakes, which is 4 times as much.

The total stopping distance of your vehicle is the sum of the 3 distances (perception distance, reaction distance, and braking distance) [6]

Here are some examples of stopping distance.

(in mph)

Perception +
Reaction Distance
(in feet)

Braking Distance
(in feet)

Total Stopping Distance
(in feet)

20 mph

44 feet

18 feet

62 feet

30 mph

66 feet

40 feet

106 feet

40 mph

88 feet

72 feet

160 feet

50 mph

110 feet

112 feet

222 feet

60 mph

132 feet

161 feet

293 feet

70 mph

154 feet

220 feet

374 feet


The total stopping distance will be affected by the conditions of the road and you can reduce your stopping distance by covering your brakes. This is putting your feet over your brakes when you are not accelerating. This will cut down your stopping distance by up to 0.75 seconds. You should do this when you are noticing a potential danger or know you may need to stop.

Adjusting Your Speed

Prepare to slow down and stop when you are approaching the following areas:

  • Traffic-controlled intersections
  • Crosswalks
  • Lanes next to parked cars
  • Parking lot entrances
  • Interchanges where vehicles enter and leave
  • Slippery or ice covered roads
  • Where children or kids play such as schools, playgrounds or parks
  • Construction Zones

What to watch out for in School Zones

You need to slow down when entering a posted school zone where children are present. This refers to 30 minutes before, during and 30 minutes after children begin arriving at the school for the beginning or the day all the way until they start leaving school at the end of the day. You’ll find the greatest number of children outside the school grounds at the beginning and the end of a school day but you should slow down at other times during the day.

Construction Zones

When you’re entering a construction zone, you are required to yield the right-of-way to works that are present in the area. In 2013, there were 75 fatalities, 4422 injuries and 7519 work zone crashes in Florida. This has decreased since 2005 but it’s still too high! [7] Pay attention to signs that warn you of construction zones ahead of time and slow down. These signs have an orange background and they protect both the workers and the driver. You should be aware of the following when entering a construction zone:

  • Expect the unexpected. Traffic lanes may have been changed to accommodate the work being done.
  • Slow down. Speeding is a major cause of work zone crashes. Keep in mind that speeding fines are doubled.
  • Don’t tailgate and leave plenty of space
  • Maintain a safe distance between your vehicle and the workers and their equipment.
  • Obey flaggers. They wear orange vests or jackets and use red flags or slow/stop signs to direct traffic.
  • Stay alert. Remove distractions that keep your full attention from the roadway. This means putting away your cell phone and don’t text.
  • Keep up with the flow of traffic. If you need to merge, do it as soon as you can, not at the last minute.
  • Give yourself plenty of time, leaving early if possible. Expect delays. If you check for traffic before you leave, you will be better prepared [8]

Make sure you are aware of the speed of your vehicle and scan the road for hazards. Maintaining a proper following distance will allow you to stop safely. You can also improve your stopping distance by covering your brakes.



Cambridge University, “Driving Conditions,” [Online]. Available: http://www.cambridge.k12.mn.us/~rob_swanson/Chapter%206%20manual.pdf.


Michigan Driver Improvement, “Chapter 3 – Collision Prevention,” [Online]. Available: https://www.michigandriverimprovement.com/collision-prevention-3.


Safe Driving Florida, “Blind Spots,” [Online]. Available: http://safedriveflorida.com/english/category/driving-safety/page/2/.


Roadtrip America, “Defensive Driving Rule,” [Online]. Available: http://www.roadtripamerica.com/forum/content.php?19-Defensive-Driving-Rule-12-Look-Down-the-Road.


I. Law, “Top 10 ways to prevent a rear-end collision,” [Online]. Available: http://www.wheels.ca/top-ten/top-10-ways-to-prevent-a-rear-end-collision/.


BBC, “Thinking, Braking and Stopping distance,” [Online]. Available: http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/forces/motionrev3.shtml.


Florida Department of Transportation, “If you thought work zone safety was ONLY our job, think again.,” [Online]. Available: http://www.fdot.gov/safety/workzonesafety/aboutus.shtm.


Federal Highway Administration, “National Work Zone Awareness Week,” [Online]. Available: https://ops.fhwa.dot.gov/wz/outreach/wz_awareness.htm.



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